PHILIPS 21PT3921, 21PT3932, 21PT3942, 21PT3952, 21PT3962 Service manual & schematics

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Page 1

Colour Television

Service

Chassis

Та	able of contents		Page	,
1.	Technical specifications		2			Video processing	diagram A6	28	30,32
2.	Connection facilities and chase	sis overview	3			Control	diagram A7	29	30,32
3.	Safety and maintenance instru	ictions	5			Front Control	diagram A8	31	30,32
4.	Mechanical instructions		7			BTSC Decoder	diagram A9	34	30,32
5.	Faultfinding and repair tips		8			NICAM/2CS	diagram A10	35	30,32
6.	Fault finding trees		15			Smart Sound	diagram A11	37	30,32
	Supply voltages diagram		19			Audio amplifier	diagram A12	36	30,32
	Blockdiagram		20			Headphone	diagram A13	37	30,32
	Testpoint overviews		21			Rear IO Cinch	diagram A14	38	30,32
7.	Electrical Diagrams and print I	ay-outs				CRT panel	diagram B	39	40
			Diagra	ım PWB		Side AV	diagram E	33	33
	Power supply	diagram A1	22	30,32	8.	Alignments		41
	Diversity tables	-	23	30,32	9.	Circuit description new circuits		46
	Horizontal deflection	diagram A2	24	30,32	10.	Directions for use		52
	Vertical deflection	diagram A3	25	30,32	11.	List of abbreviations		61
	Synchronisation	diagram A4	26	30,32	12.	Spare parts list		63
	Tuner and VIF	diagram A5	27	30,32

^©Copyright reserved 1999 Philips Consumer Electronics B.V. Eindhoven, The Netherlands. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise without the prior permision of Philips.

Published by JR9964 TV Service Department Printed in The Netherlands

Subject to modification

(B) 4822 727 21704

Page 2

2 Connection facilities and chassis overview

2.1 Specification of the terminal sockets

Figure 2-1

2.1.3 Headphone

- Jack


2.1.1	Inputs (AV1,	AV2 and	Side AV)

Cinch CVBS (yellow)(1Vpp +/- 3dB 75Ω) Cinch Audio R (red) (0.2-2VRMS 10kΩ) Cinch Audio L (white) (0.2-2VRMS 10kΩ)

2.1.2 Outputs (MONITOR out)

Cinch CVBS (yellow) (1Vpp +/- 3dB 75Ω) Cinch Audio R (red) (0.5VRMS < 1kΩ)</li> Cinch Audio L (white) (0.5VRMS < 1kΩ)</li>

2.1.4	SVHS
	1- 2- 3- 4-	Ground Ground Υ (1Vpp +/- 3dB 75Ω) C (0.3Vpp +/- 3dB 75Ω)
~ ~		tion drawing

8-600Ω (4mW)

CL 86532104_004ap.eps 010499

Page 3

L9.1A 3 Safety and maintenance instructions

Safety instructions for repairs

1. Safety regulations require that during a repair:
- the set should be connected to the mains via an isolating transformer:
- safety components, indicated by the symbol (see fig 3.1), should be replaced by components identical to the original ones:
- when replacing the CRT, safety goggles must be worn.
2. Safety regulations require that after a repair the set must be returned in its original condition. In particular attention should be paid to the following points.
- As a strict precaution, we advise you to resolder the solder joints through which the horizontal deflection current is flowing, in particular:
  - all pins of the line output transformer (LOT);
  - fly-back capacitor(s);
  - S-correction capacitor(s):
  - line output transistor;
  - pins of the connector with wires to the deflection
  - other components through which the deflection current flows.

Note: This resoldering is advised to prevent bad connections due to metal fatigue in solder joints and is therefore only necessary for television sets older than 2 years. The wire trees and EHT cable should be routed correctly and fixed with the mounted cable clamps.

The insulation of the mains lead should be checked for external damage
The mains lead strain relief should be checked for its function in order to avoid touching the CRT, hot components or heat sinks.
The electrical DC resistance between the mains plug and the secondary side should be checked (only for sets which have a mains isolated power supply). This check can be done as follows
- unplug the mains cord and connect a wire between the two pins of the mains plug;
- set the mains switch to the on position (keep the mains cord unplugged!);
- measure the resistance value between the pins of the mains plug and the metal shielding of the tuner or the aerial connection on the set. The reading should be between 4.5 MΩ and 12 MΩ;
- switch off the TV and remove the wire between the two pins of the mains plug
The cabinet should be checked for defects to avoid touching of any inner parts by the customer.

3.2 Maintenance instruction

It is recommended to have a maintenance inspection carried out by a qualified service employee. The interval depends on the usage conditions:

When the set is used under normal circumstances, for example in a living room, the recommended interval is 3 to 5 years.

When the set is used in circumstances with higher dust, grease or moisture levels, for example in a kitchen, the recommended interval is 1 year.
- The maintenance inspection contains the following actions:
- Execute the above mentioned 'general repair instruction'.
- Clean the power supply and deflection circuitry on the chassis
- Clean the picture tube panel and the neck of the picture tube

3.3 Warnings

1. ESD

All ICs and many other semiconductors are susceptible to electrostatic discharges (ESD). Careless handling during repair can reduce life drastically. When repairing, make sure that you are connected with the same potential as the mass of the set by a wristband with resistance. Keep components and tools also at this same potential

complete kit ESD3 small table mat, wristband connectionbox, extensioncable and earthcable 4822 310 10671
wristband tester 4822 344 13999
2. In order to prevent damage to ICs and transistors, all highvoltage flashovers must be avoided. In order to prevent damage to the picture tube, the method shown in Fig. 3.2 should be used to discharge the picture tube. Use a highvoltage probe and a multimeter (position DC-V). Discharge until the meter reading is 0V (after approx. 30s).
Together with the deflection unit and any multipole unit, the flat square picture tubes used from an integrated unit. The deflection and the multipole units are set optimally at the factory. Adjustment of this unit during repair is therefore not recommended
4. Be careful during measurements in the high-voltage section and on the picture tube.
5. Never replace modules or other components while the unit is switched on.
When making settings, use plastic rather than metal tools This will prevent any short circuits and the danger of a circuit becoming unstable.
7. Wear safety goggles during replacement of the picture tube

Notes

1. The direct voltages and oscillograms should be measured with regard to the tuner earth . or hot earth as this is called (see fig. 3.3)
2. The direct voltages and oscillograms shown in the diagrams are indicative and should be measured in the Service Default Mode (see chapter 8) with a colour bar signal and stereo sound (L:3 kHz, R:1 kHz unless stated otherwise) and picture carrier at 475.25 MHz.
3. Where necessary, the oscillograms and direct voltages are measured with and without aerial signal. Voltages in the power supply section are measured both for normal operation and in standby . These values are indicated by means of the appropriate symbols (see fig. 3.3)
4. The picture tube PWB has printed spark gaps. Each spark gap is connected between an electrode of the picture tube and the Aquadag coating
5. The semiconductors indicated in the circuit diagram and in the parts lists are completely interchangeable per position with the semiconductors in the unit, irrespective of the type indication on these semiconductors.

Page 4

3 Safety and maintenance instructions

tuner earth tuner aarde la masse du tuner Tuner-Erde massa del tuner tierra del sintonizador

with aerial signal met antenne signaal avec signal d'antenne mit Antennensignal con segnale d'antenna con la señal de antena

normal condition normaal bedrijf fonctionnement normal normaler Betrieb funzionamento normale funcionamiento normal

Figure 3-3

hot earth hete aarde la terre directe heißen Erde massa calda tierra caliente

without aerial signal zonder antenne signaal sans signal d'antenne .ohne Antennensignal senza segnale d'antenna sin la señal de antena

stand by stand by position de veille in Bereitschaft modo di attesa posición de espera

L9.1A

Page 5

4 Me

Mechanical instructions

4.1 Service positions

See figure 4.1 for the service position.

1. Disconnect the connecting cable feeding the right-hand speaker, also disconnect the degaussing cable.
2. The mono-carrier is removed by pushing the two centre clips (1) at both chassis brackets outwards and pulling the panel forward. (2)
Flip the mono-carrier over so that the component side of the board faces towards the CRT.
4. Slide the metal heat sink underneath the left chassis bracket (3) until the carrier is locked in position.

Page 6

5 Fault finding and repair tips

This chapter includes information covering:

5.1 Test points
5.2 Service Modes and Dealer Service Tool (DST)
5.3 The menus and submenus
5.4 Error code buffer and error codes
5.5 The "blinking LED" procedure
5.6 Trouble shooting tips
5.7 Customer Service Mode (CSM)
5.8 Computer Aided Repair ( ComPair )
5.9 Ordering ComPair

5.1 Test points

The L9 chassis is equipped with easily identifiable test points. These are clearly marked on the PCB. The test points refer to specific functional blocks, these are:

A1-A2-A3, etc.: Test points for the BTSC decoder (A9), Nicam + 2CS decoder (A10) and Audio Amplifier (A12)
C1-C2-C3, etc.: Test points for the control circuit (A7)/ front control (A8)
F1-F2-F3, etc.: Test points for the vertical deflection circuit (A3)
I1-I2-I3, etc.: Test points for the tuner + Video IF circuit (A5)
L1-L2-L3, etc.: Test points for the horizontal deflection circuit (A2)
P1-P2-P3, etc.: Test points for the power supply (A1)
S1-S2-S3, etc.: Test points for the synchronisation circuit (A4)
V1-V2-V3, etc.: Test points for the video processing circuitry (A6) / CRT panel (B)

Measurements are performed under the following conditions:

Video: colour bar signal; audio: 3kHz left, 1kHz right

5.2 Service modes and Dealer Service Tool (DST)

For easy installation and diagnosis, the dealer service tool (DST) RC7150 can be used. When there is no picture (to access the error code buffer via the OSD). The DST can enable to set to display the entire contents of the error code buffers by using the flashing LED procedure.

Important Note: The L9 does not incorporate two way Infra red communication.

The part number for the DST (RC7150) is 4822 218 21232.

5.2.1 Installation features for the dealer

The dealer can use the RC7150 for programming the TV-set with presets. 10 Different program tables can be programmed into the DST via a GFL TV, MD or MG set (downloading from the TV to the DST; for example see the GFL service manuals). For an explanation of the installation features of the DST, please see the directions of use for use of the DST (for the L9 chassis, download code 4 should be used).

5.2.2 Diagnosis features for the servicer

L9 models can be put into either of the two available service modes by using the RC7150. These are the Service Default Mode (SDM) and the Service Alignment Mode (SAM).

5.2.3 Service Default Mode (SDM)

The purpose of the SDM is:

Used to provide a pre-defined situation (pre-defined parameters), so that the same measurements can be obtained as per the service manual.
Overrides the 5V protection when the internal method of SDM is used (connecting together pin M24 and pin M25).
starts the LED flashing procedure
Setting up of options codes
Inspect the error buffer

Entering the SDM:

By transmitting the "DEFAULT" command with the RC7150 Dealer Service Tool (this works both while the set is in normal operation mode or in the SAM)
Standard RC sequence 062596 followed by the key "MENU"
By connecting test-pins M25 and M24 together (on the mono-carrier) while switching on the set. After switching on the set the link should be removed (Caution!! By entering the SDM mode you override the 5V protections).

Exit the SDM:

Switch the set to Standby or press EXIT on the DST (the error buffer is also cleared).

Note: When the mains power is switched off while the set is in SDM, the set will switch to SDM immediately when the mains is switched on again. (The error buffer will not be cleared ).

The SDM sets the following pre-defined conditions:

Pal/Secam sets: tuning at 475.25 PAL
NTSC sets : tuning channel 3 at 61.25MHz

Volume level is set to 25% (of the maximum volume level). Other picture and sound settings are set to 50%. The following functions are "ignored" in SDM since they interfere with diagnosing/repairing a set. "Ignoring" means that the event that is triggered is not executed, the setting remains unchanged.

(Sleep)Timer
Blue mute
Auto switch off
Hotel or Hospitality Mode
Child lock or Parental lock
Skipping, blanking of "Not favourite" present/channels
Automatic storing of Personal Preset settings
Automatic user menu time-out

All other controls operate normally.

5.2.4 Special functions in SDM

Access to normal user menu

Pressing the "MENU" button on the remote control will enter the normal user menu (TV lock, Installation, Brightness, colour and contrast) while "SMD" remains displayed in top of screen). Pressing the "MENU" key again will return to the last SDM status.

Error buffer

Pressing the "OSD" button of the remote control shows all OSD (incl. error buffer).

Access to SAM

By pressing the "CHANNEL DOWN" and "VOLUME DOWN" buttons on the local keyboard simultaneously the set switches from SDM to SAM or pressing "ALIGN" on the DST

Page 7

L9.1A

Fault finding and repair tips

In the SDM the following information is displayed on the screen:

Figure 5-1 : Service Default Mode screens and structure

Explanation notes/references:

(1) "LLLL" Operation hours timer (hexadecimal)

(2) Software identification of the main micro controller (L90BBC X.Y)

L90 is the chassis name for L9.0E
BBC is a 2 letter and 1 digit combination that indicates the software type and the supported languages:
X = (main version number)
Y = (subversion number) BB = (range specification )

(3) "SDM" To indicate that the TV set is in de service mode

(4) "OP" Options Code consist of 2 characters. It is possible to change each option code

"VALUE" The value of the selected option ( ON/OFF or a combination of 2 letters )

"XXX" Value of the options bytes ( OB1 .. OB7)

"ERR" The last five detected errors; The left most number indicates the most recent error detected.

The MENU UP or MENU DOWN command can be used to select the next/previous option; The MENU LEFT and MENU RIGHT command can be used to change the option value.

Remark: When the option-code RC = OFF, the P+ and the Pkey have the same functions as the MENU UP/DOWN keys while the VOL+ and the VOL- key have the same function as the MENU LEFT/RIGHT keys. It is not possible to change the channel pre-set or to adjust the volume when in SAM/SDM menu when the option RC = OFF.

Using a L9 remote control, option-code RC = ON, the P+, P-, VOL- and VOL+ can be used to change the pre-set and/or to adapt the volume, while the menu-cursor keys are used to select the option and to change its value.

For an extended overview of the option codes see Chapter 8 - Options

5.2.5 Service Alianment Mode (SAM)

The SAM allows adjustment of the Demodulator I.F, align the white tone, adjust the picture geometry and sound adjustments.

For easy identification of the SAM mode, "SAM" is displayed in the top of the right side of the screen

Entering SAM:

By transmitting the "ALIGN" command with the RC7150 Dealer Service Tool
By pressing the "CHANNEL DOWN" and "VOLUME DOWN" key on the local keyboard simultaneously when the set is in SDM
Standard RC sequence 062596 followed by the key "OSD"
By shorting test-pins M28 and M29 on the mono-carrier while switching on the set. After switching on the set the short-circuit can be removed. (Caution!! Override of 5V protections).

Exiting the SAM:

Switch the set to standby or press EXIT on the DST (the error buffer is cleared).

Note: When the mains power is switched off while the set is in SAM, the set will switch to SAM immediately when the mains is switched on again. ( The error buffer will not be cleared ).

In the SAM the following information is displayed on the screen:

Page 8

Page 9

L9.1A 5 Fault finding and repair tips

Access to normal user menu

Pressing the "MENU" button on the remote control will enter the normal user menu (TV lock, installation, brightness, colour and contrast ) while "SAM" remains displayed in top of screen. Pressing the "MENU" key again will return to the last SAM

Pressing the "OSD" button of the remote control shows only "SAM" in the top of screen

Pressing the "DEFAULT" button on the DST

SAM menu control

Menu items (AKB, VSB, Tuner, White tone, Geometry and Sound) can be selected with the MENU Up or MENU DOWN key. Entry into the selected items (sub menus) is done by the MENU LEFT or MENU RIGHT key. The selected item will be highlighted.

With the cursor LEFT/RIGHT keys, it is possible to increase/ decease the value of the selected item.

The menus and submenus

The tuner sub menu contains the following items:

IF PLL: PLL Alignment for all PAL/SECAM systems
AFW AFC Window
AGC: AGC take-over point
YD: Default value = 12 ; Do not align
CL: Default value = 4 ; Do not align - AFA
AFB

The items AFA and AFB can not be selected, they are for monitoring purposes only.

The commands MENU UP and MENU DOWN are used to select the next/previous item.

The commands MENU LEFT and MENU RIGHT are used to increase/decrease the value of the selected item. The changed values will be send directly to the related hardware.

The item values are stored in NVM if this sub menu is left.

5.3.2 White tone sub menu

The white tone sub menu contains the following items:

NORMAL BED
NORMAL GREEN
NORMAL BLUE
DELTA COOL RED
DELTA COOL BLUE
DELTA COOL GREEN
DELTA WARM RED
DELTA WARM BLUE
DELTA WARM GREEN

OSD is kept to a minimum in this menu, in order to make white tone alignment possible.

The commands MENU UP and MENU DOWN are used to select the next/previous item.

The commands MENU LEFT and MENU RIGHT are used to increase/decrease the value of the selected item. The changed values will be send directly to the related hardware.

The item values are stored in NVM if this sub menu is left

The Contrast Plus feature (black stretch) is set to OFF when the white tone submenu is entered.

5.3.3 Audio sub menu

The tuner sub menu contains the following items:

AF-M: Default value = 232 : Do not align
AT: Default value = 4 ; Do not align
STEREO: Default value = 15 ; Do not align
DUAL: Default value = 12 ; Do not align

The sound adjustments sub menu is not available in Mono sets

The presence of an item in the menu is dependent on the selected soundboard (option SB).

The commands MENU UP and MENU DOWN are used to select the next/previous item.

The commands MENU LEFT and MENU RIGHT are used to increase/decrease the value of the selected item. The changed values will be sent directly to the related hardware.

The item values are stored in NVM if this sub menu is left.

5.3.4 Geometry sub menu

The geometry sub menu contains the following items:

SBL : Service blanking
VSL : Vertical slope
VAM : Vertical amplitude
VSH · Vertical shift
HSH : Horizontal shift
VSC · Vertical S correction
H60 : Default value = 10 : Do not align
V60 : Default value = 12 ; Do not align
EWC : E-W corner
EWT : E-W trapezium
EWP : E-W parabola
EWW : E-W width

5.4 Error code buffer and error codes

5.4.1 Error code buffer

The error code buffer contains all errors detected since the last time the buffer was erased. The buffer is written from left to riaht.

when an error occurs that is not vet in the error code buffer. the error is written at the left side and all other errors shift one position to the right
the error code buffer will be cleared in the following cases: 1. exiting SDM or SAM with the "Standby" command on the remote control
- 2. transmitting the commands "EXIT" with the DST (BC7150)
- 3. transmitting the commands "DIAGNOSE-9-9-OK" with
By leaving SDM or SAM with the mains switch, the error buffer is not reset

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5 Fault finding and repair tips

Examples:

ERROR: 0 : No errors detected

ERROR: 6 0 : Error code 6 is the last and only detected error

ERROR: 5 6 0 : Error code 6 was first detected and error code 5 is the last detected (newest) error

5.4.2 Error codes

In the case of non-intermittent faults, clear the error buffer before starting the repair to prevent "old" error codes being present. If possible check the entire contents of the error buffers. In some situations an error code is only the RESULT of another error code (and not the actual cause).

Note: a fault in the protection detection circuitry can also lead to a protection.

Error 0 = No error

Error 1 = X-ray (Only for USA sets)

Error 2 = High beam current protection and E/W Horizontal protection

High beam protection active; set is switched to protection; error code 2 is placed in the error buffer; the LED will blink 2 times ( repeatedly ).

As the name implies, the cause of this protection is a too high beam current (bright screen with flyback lines). Check whether the +200V supply to the CRT panel is present. If the voltage is present, the most likely cause is a fault on the CRT panel. Disconnect the CRT panel to determine the cause. If the +200V voltage is not present, check R3340 (CRT panel - B), R3485 and D6485 (Horizontal Deflection - A2)

EW protection:

If this protection is active, the causes could be one of the following;

horizontal deflection coil 5445
linearity coil 5457
S-correction capacitor 2466/2468
flyback capacitor 2465
line output stage
short circuit of:
flyback diode 6460
EW transformer (bridge coil) 5465/5470 or 5463/5471 (version dependent)
S-correction capacitor 2457
EW power-transistor 7460 or driver-transistor 7461

Error 3 = Vertical / Frame protection

There are no pulses detected at pin 47 of the main microprocessor 7600 ( panel A7 ).

If this protection is active, the causes could be one of the following items;

- IC 7401 is faulty

Open circuit of vertical deflection coil
Vlotaux +11V not present and/or Vlotaux -11V not present Resistor 3409
Resistor 340

Error 4 = Sound processor I2C error (MSP3415D or MSP3435 or BSP3501)

Sound processor does not respond to the micro controller

Error 5 = Bimos start-up error ( POR bit )

Bimos start-up register is corrupted or the I2C line to the Bimos is always low or no supply at pin 12 of the Bimos). This error is usually detected during start-up and hence will prevent the set from starting up.

Error 6 = Bimos (TDA884x) I2C error

Note that this error may also be reported as a result of error codes 4 (in that case the Bimos might not be the actual problem)

Error 7 = General I2C error. This will occur in the following cases:

SCL or SDA is shorted to ground
SCL is shorted to SDA
SDA or SCL connection at the micro controller is open circuit.

Error 8 = Microprocessor internal RAM error

The micro controller internal RAM test indicated an error of the micro controller internal memory (tested during start-up);

Error 9 = EEPROM Configuration error ( Checksum error ); EEPROM is corrupted.

Error 10 = I2C error EEPROM error. NV memory (EEPROM) does not respond to the micro controller

Error 11 = I2C error PLL tuner. Tuner is corrupted or the I2C line to the Tuner is low or no supply voltage present at pin 9, pin 6 or pin 7 of the tuner.

Error 12 = Black current loop instability protection. The black current could not be stabilised. The possible cause could be a defect in one or more of the RGB amplifiers, RGB guns or RGB driving signals.

5.5 The "blinking LED" procedure

The contents of the error buffer can also be made visible via the "blinking LED" procedure. This is especially useful when there is no picture. There are two methods of access:

1. When the SDM is entered, the LED will blink the number of times, equal to the value of the error codes in the errorbuffer, starting with the first error-code, pause, second error-code, pause etc. (repeatedly).
2. With the DST all error codes in the error buffer can be made visible. Transmit the command: "DIAGNOSE x OK" where x is the position in the error buffer to be made visible x ranges from 1, (the last (actual) error) to 6 (the first error). The LED will operate in the same way as in point 1, but now for the error code on position x.

Example:

Error code position: 1 2 3 4 5

Error buffer: 8 9 5 0 0

after entering SDM: blink (8x) pause blink (8x) etc.
after transmitting "DIAGNOSE- 2- OK" with the DST blink (9x) - pause - blink (9x) - etc.
after transmitting "DIAGNOSE- 3- OK" with the DST blink(5x) - pause - blink(5x) - etc.

Page 11

12

Fault finding and repair tips

after transmitting "DIAGNOSE- 4- OK" with the DST nothing happens

L9.1A 5

5.6 TROUBLE SHOOTING TIPS

In this paragraph some trouble shooting tips for the deflection and power supply circuitry are described. For detailed diagnostics, use the fault finding tree or use ComPair.

5.6.1 THE DEFLECTION CIRCUIT:

Check that the +VBATT (140V) is present across 2551 ( A1 POWER SUPPLY). If the voltage is not present, disconnect coil 5551 (A1 Power Supply) (Horizontal deflection stage is disconnected). If the voltage is present then the fault might be caused by the deflection circuit. Possible Candidates Are:
- Transistor 7460 is faulty
- The driver circuit around transistor 7461 is faulty
- No horizontal drive signal coming from the BIMOS 7250-D pin 40 (A4 - Synchronisation)
2. Note: If the Collector of 7460 is shorted to the Emitter, a tripping noise will be heard from the power supply circuit.
3. To determine whether the fault is present in the horizontal deflection circuit or in the E/W circuit (A2 Horizontal Deflection), de-solder jumper 9465 and insert a jumper into position number 9461. This disables the E/W protection. If the basic deflection stage now works correctly (parabolic picture) then the fault is present in the E/W circuit. If there is still no horizontal deflection, then the fault is present in the basic deflection circuitry.
4. Also don't forget the protection circuits in the line output stage. If any of these circuits are activated, the set will shut down. Depending on the protection, the led will blink according to the fault defined. In order to determine which protection circuit is active, isolation of each separate circuit is necessary. These protection circuits are:
- High beam current protection ( LED blinks repetitively 2 times ) - CRT panel ( B )
- E/W Horizontal protection (LED blinks repetitively 2 times) - Horizontal deflection (A2)
- Vertical protection (LED blinks repetitively 3 times) -Vertical deflection (A3)

5.6.2 THE POWER SUPPLY

To trouble shoot the L9 SMPS, first check the Vaux voltage on C2561. If this voltage is not present, check fuse F1572 and D6560. If F1572 or D6560 is not open circuit, the problem might be caused on the primary side of the switching supply. Check the output of the bridge rectifier on the C2508 for approximately 300V DC. If this voltage is missing, check the bridge rectifier 6505 and the fuse 1500. If fuse F1500 is found to be open circuit, check MOSFET 7518 to make sure that there is no short circuit present and check R3518. If the 300V DC is present on C2508, check for a start-up voltage of approx. 13V on pin 1 of IC7520. If no start-up voltage is present, check if R3510 is open; zener 6510 is a short-circuit. It is necessary to have a feedback signal from the hot primary side of switch mode transformer T5545 at pin 8 and pin 9 for the power supply to oscillate. If this start-up voltage is present on pin 1 of IC7520 and the supply is not oscillating, check R3529 and D6540

Check for a drive signal at the gate of MOSFET 7518, square wave signal - P2. Check pin 3 of IC7520, R3525 and D6514

To determined whether OVP is active, check whether Vaux is present at C2561.

5.7 Customer Service Mode (CSM)

All L9.1 sets are equipped with the "Customer Service Mode" (CSM). CSM is a special service mode that can be activated and deactivated by the customer, following a request from the service technician/dealer perhaps during a telephone conversation to identify the status of the set. This CSM is a 'read only' mode, therefore modifications or changes while the set is in this mode are not possible.

Entering the Customer Service Mode. The Customer Service Mode can be switched on by pressing simultaneously the button (MUTE) on the remote control and any key on the control buttons (P+, P-, VOL +, VOL -) on the TV for at least 4 seconds.

When the CSM is activated:

picture and sound settings are set to nominal levels
"Service unfriendly modes" are ignored

Exit the Customer Service Mode.

The Customer Service Mode will switch off after:

pressing any key on the remote control handset (except "P+" or "P-")
switching off the TV set with the mains switch.

All settings that were changed when CSM was activated are set back to the initial values

5.7.1 The Customer Service Mode information screen

The following information is displayed on screen:

Line number for every line (to make CSM language independent)
Operating hours
Software version L90BBC X.Y)
Text "CSM" on the first line
Error buffer contents
Option code information
Configuration information
Service unfriendly modes

Figure 5-3 : Screen lay-out Customer Service Mode

SYS: xxxxxx = xxxxxx is the SYSTEM THAT IS SET FOR THIS PRESET

NOT TUNED = no ident signal present

TIMER = (SLEEP) TIMER is activated

LOCKED = Channel/preset locked via parental lock, child lock

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5 Fault finding and repair tips

HOTEL = HOTEL mode activated; HOSPITAL = HOSPITAL mode activated

VOL LIM > = Volume limiter activated and set to >

5.7.2 Exit

Any key (RC or local keyboard) except "channel up" / "channel down" (standby switched to standby, mains OFF switches set off, other keys switch to normal operation)

5.8 ComPair

5.8.1 Introduction

ComPair (Computer Aided Repair) is a service tool for Philips Consumer Electronics products. ComPair is a further development on the DST service remote control allowing faster and more accurate diagnostics. ComPair has three big advantages:

ComPair helps you to quickly get an understanding how to repair the L9.1A in short time by guiding you step by step through the repair procedures.
ComPair allows very detailed diagnostics (on I2C level) and is therefore capable of accurately indicating problem areas. You do not have to know anything about I2C commands yourself; ComPair takes care of this.
ComPair speeds up the repair time since it can automatically communicate with the L9.1A (when the micro processor is working) and all repair information is directly available. When ComPair is installed together with the SearchMan L9.1A electronic manual, schematics and PCBs are only a mouse-click away.

ComPair consists of a Windows based fault finding program and an interface box between PC and the (defective) product. The ComPair interface box is connected to the PC via a serial or RS232 cable. In case of the L9.1A chassis, the ComPair interface box and the L9 communicate via an I2C cable (bidirectional) and via infra red communication (uni-directional; from ComPair interface box to L9.1A)

The ComPair fault finding program is able to determine the problem of the defective television. ComPair can gather diagnostic information in 2 ways:

1. Communication to the television (automatic)
2. Asking questions to you (manually)

ComPair combines this information with the repair information in its database to find out how to repair the L9.1A.

Automatic information gathering

Reading out the error buffer, ComPair can automatically read out the contents of the entire error buffer.

Diagnosis on I2C level. ComPair can access the I2C bus of the television. ComPair can send and receive I2C commands to the micro controller of the television. In this way it is possible for ComPair to communicate (read and write) to devices on the I2C busses of the L9.1A.

Manual information gathering

Automatic diagnosis is only possible if the micro controller of the television is working correctly and only to a certain extend. When this is not the case, ComPair will guide you through the fault finding tree by asking you questions and showing you examples. You can answer by clicking on a link (e.g. text or an waveform pictures) that will bring you to the next step in the faultfinding process.

A question could be: Do you see snow? (Click on the correct answer)

YES / NO

An example can be: Measure testpoint I7 and click on the correct oscillogram you see on the oscilloscope

Figure 5-4

By a combination of automatic diagnostics and an interactive question/answer procedure, ComPair will enable you to find most problems in a fast and effective way.

Additional features

Beside fault finding, ComPair provides some additional features like:

Uploading/downloading of presets
Managing of preset lists
Emulation of the Dealer Service Tool

SearchMan ( Electronic Service Manual )

If both ComPair and SearchMan are installed, all the Schematics and PCBs of the faulty set are available when clicking on the hyper-link of a schematic or a PCB in ComPair

Example: Measure the DC-voltage on capacitor C2568 ( Schematic/Panel ) at the Monocarrier.

Clicking on the PCB hyper-link, automatically shows the PCB with a high-lighted capacitor C2568. Clicking on the schematic hyper-link, automatically shows the position of a high-lighted capacitor at the schematic.

5.8.2 Connecting the ComPair interface

The ComPair Browser software should be installed and setup before connecting ComPair to the L9.1A. (See the ComPair Browser Quick Reference Card for installation instructions.)

Connect the RS232 interface cable to a free serial (COMM) port on the PC and the ComPair interface PC connector (connector marked with "PC").
2. Place the ComPair interface box straight in front of the television with the infrared window (marked "IR") directed to the television LED. The distance between ComPair interface and television should be between 0.3 and 0.6 meter. (Note: make sure that (also) in the service position, the ComPair interface infra red window is pointed to the standby LED of the television set (no objects should block the infra red beam)
3. Connect the mains adapter to the connector marked "POWER 9V DC" on the ComPair interface
4. Switch the ComPair interface OFF
5. Switch the television set OFF with the mains switch
Remove the rear cover of the television set
Connect the interface cable (4822 727 21641) to the connector on the rear side of the ComPair interface that is marked "I2C" (See Figure 5.6)

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L9.1A

Fault finding and repair tips

8. Connect the other end of the interface cable to the ComPair connector on the monocarrier (see figure 5.7)
Plug the mains adapter in the mains outlet and switch ON the interface. The green and red LEDs light up together. The red LED extinguishes after approx. 1 second (the green LED remains lit).

Start-up ComPair and select "File" menu, "Open....; select "L9.1A Fault finding" and click "OK"
Click on the > icon to switch ON the communication mode (the red LED on the ComPair interface wil light up)
12. Switch on the television set with the mains switch
When the set is in standby. Click on "Start-up in ComPair mode from standby" in the ComPair L9.1A fault finding tree, otherwise continue.

Figure 5-6

The set has now started up in ComPair mode. Follow the instruction in the L9.1A fault finding tree to diagnose the set. Note that the OSD works but that the actual user control is disabled

5.8.3 Preset installation

Presets can be installed in 2 ways with the L9.1A.

Via infra red
- only sending TO the television
- the rearcover does NOT have to be removed

Click on "File" "Open" and select "TV - use ComPair as DST" to use infra red

Via cable
- sending TO the television and reading FROM the television
- the rearcover has to be removed

Click on "File" "Open" and select "L9.1A fault finding" to use the cable

Presets can be installed via menu "Tools", "Installation", "Presets".

5.9 Ordering ComPair

ComPair order codes:

Starterkit ComPair+SearchMan software + ComPair interface (excluding transformer): 4822 727 21629

ComPair interface (excluding transformer): 4822 727 21631
ComPair transformer (continental) Europe: 4822 727 21632
ComPair transformer United Kingdom: 4822 727 21633
Starterkit ComPair software: 4822 727 21634
Starterkit SearchMan software: 4822 727 21635
Starterkit ComPair+SearchMan software: 4822 727 21636
ComPair CD (update): 4822 727 21637
SearchMan CD (update): 4822 727 21638
ComPair interface cable (for L9): 4822 727 21641

Figure 5-7

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6 Fault finding trees, diagrams and overviews

L9.1A

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and overviews

Remark : n normal operation the Red LED lights in half intensity and in tandby-mode the LED lights in full intensity

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(A1) means Drawing A1 <P1> means Test point P1

CL 86532104_034.eps 190299

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6 Fault finding trees, diagrams and overviews

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ams and overviews

L9.1A

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CL 86532104_035.eps

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Black current calibration loc

6 Fault finding trees, diagrams and overviews

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overviews L9.1A 18

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6 Fault finding trees, diagrams and overviews

μC

7601 ST24W0481

100

7250 TD8844

7821 TDA9851

DECODER

7833 MSP3415D NICAM

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6 Fault finding trees, diagrams and overviews

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6 Fault finding trees, diagrams and overviews

P1 () A10 LEFT OUT A19 L-S1 H FLYBK C2 SDA uP L5 VIOT AUX-11 NAAAA, 1V / div DO 0.5V / div AC 1V / div DC 50V / div DC 2V / div DC 0.2V / div AC 0.2V / div AC 20µs / div 20us / div 5ms/div 5ms / div 0.2ms/div 0.2ms/div 20µs / div S2 HDRIVE C3 SCL uP L9 VLOT AUX+11 A11 RIGHT OUT MM ┶╾╝╌╘┯┙╴┡╍┾┙ 2V / div DC 0.2V / div DC 0.5V / div AC 1V / div DC 2V / div DC 0.2V / div AC 20µs / div 20µs / div 10µs / div 10µs / div 5ms / div 0.5ms / div S3 VDRIVE+ V11 R P2 () L1 () 0.3V DC A12 AUDIO OUT L/MONO L3 () 138V DC 1.6.190 V DC -----L7 ① 32.5V DC 1V / div DC 0 5V / div AC 1V / div DC 2V / div DC 0.5V / div AC 17 () 28V DC 5ms / div 20us / div 10us/div 10us / div 0.2ms / div L8 ① 46V DC SA VORIVE-P3 ① 15V DC A13 AUDIO OUT R L8 () 30V DC P3 () 12V DC L10.5V DC --------------------------------------P4 (1) 138V DC ╘┙┙┼┝╋╍╢╎ P4 (^I) 138V DC 1V / div DC 0.5V / div AC 1V / div DC 0.5V / div AC P5 (11.8V DC 5ms / div 20µs / div 10µs / div 0.5ms / div P5 () 9.8V DC V7 V13 B F1 VDRIVE + A14 SCL 7833 P6 ① 16V DC P6 (¹) 13.8V DC n hh P7 8V DC 0.5V / div AC 0.5V / div AC 1V / div DC 0.5V / div DC 20us / div 10µs / div 20us / div 10us / div 5ms / div F2 VDBIVE A15 SDA 7833 15 SCL TUNEF 1 () HDRIVE ┪┓╓┾╍┽┑╻╓┉╴ ┿^┲╋<mark>╞╴</mark>╋╺┙┍╼┲┓ 50V / div DC 2V / div DC 0 1V / div DC 0.5V / div DC 1V / div DC 1V / div D 20µs / div 20us / div 5ms / div 20us / div 10µs / div 10us / div A16 R+ V9 SCL 7250 0.2V / div AC 1V / div DC 1V / div DC 50V / div DC 2V / div DC 10V / div D0 20µs / div 10µs / div 10µs / div 20µs / div 5ms / div 0.5ms / div V1 CVBS-INT V10 SDA 7250 V16 F4 V FLYBK Δ17 B-han Para VVV 0.5V / div AC 1V / div DC 50V / div DC 100V / div DC 2V / div DC 0.2V / div AC 0.5ms / div 20us / div 20us / div 10us / div 20µs / div 5ms / div A18 L+ ΛΛΛΛΛΛ ₩₩₩ ┢╫╞╋┼┥ --- = 0V 0.5V / div AC 1V / div DC 50V / div DC 5V / div DC 0.5V / div D 0.2V / div AC CL 86532104_020.EP 0.2 v / ulv A 20µs / div 0.5µs / div 5ms / div

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lay-outs

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DIVERSITY TABLE FOR ALL ITEM NO. MARKED WITH- ITEM FR_CIS LR FR_NONCIS HR CIS PS_FR_LIS NONCIS ITV 140V 130V 0231 YES	2X3w/5w AUDIO T1.0 T2.5A 2200/25V 1000/	A T1.
DIVERSITY TABLE FOR ALL ITEM NO. MARKED WITH+ ITEM FR_CIS 251/291 NP LR FR_OIS 251/291 NP PS_FR_US 251/291 NP PS_FR_US PS_FR_US PS_FR_VS PS_FR_US PS_FR_VS PS_FR_US PS_FR_VS PS_FR_US PS_FR_VS PS_FR_US PS_FR_VS PS_FR_US PS_FR_VS PS_FR_US PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS PS_FR_VS	2X3w/5w 2X1w AUDIO AUDIO T1.0 T2.5A T1.0 Z200/25V 1000/	1x AUD A T1 6V 1000
ITEM FR_CIS LR FR_NONCIS HR CIS PS_FR_US PS_FR_LA HR PS_FR Difference PS_FR ITV 140V VBATT 0231 YES ··· YES ···· ···· ···	2X3w/5w 2X1w AUDIO AUDIO T1.0 T2.5A T1.0 2200/25V 1000/	1X AUD A T1.
0231 YES	T1.0 T2.5A 2200/25V 1000/	A T1.
1571	T1.0 T2.5A 2200/25V 1000/	4 T1.
1573 YES	12.5A 2200/25V 1000/ 1000/	6V 1000.
7501 71.5	2200/25v 1000/	6V 1000.
2561 3300u 1000u 3300u	2200/25V 1000/	6V 1000
2571 <	2200/25V 1000/	6V 1000,
572 330p	1000/	6V 1000/
577 503 220V/9R 110V/10R 220V/9R 505 507 220V/9R 507 220V/9R 507 2R2/5W 2R2/5W 500 2R2/5W 33K/3W 500 <		6V 1000.
3003 220073K 110710K 220073K 110710K
SUD TES
S10 33K/3w S3K/3w
515 NTC 2R5 570 10K 15K 571 10K 15K 571 10K 15K 572 DME2810 DME2820
1570 10K 15K 571 10K 15K 572 DME2810 DME2820
571 160K 150K 150K 502 DME2820 160K 150K
NEZ ELDMEZXIU B E. E. T. E.

bb0 YES	YES
576 YFS
500 BZX79-C30
501 BZX79-C30
505 GBUGJL GBU4JL GBU4JL GBUGJL GBUGJL GBU4JL GBUGJL
	EGP200	RYV27
	FGP20D	121121
	EGP20D
500 YES YES
501 YES YES
302 ···· YES YES ···· YES YES ···· ···
1503 YES YES
1505 YES YES
1546 YES YES TES YES	VEO	VEC
509	YES	YES

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print lay-outs

4 5 6 7 8 9 3

L9.1A 23

DIVERSITY TABLE FOR POWER SUPPLY

								I
1	ly table f	OR ALL IT	EM NO. MAR	KED WITH*
	PS_FR_US	PS_FR_LA	HR 251/291 CHINA	PS_FR NONCIS IND	ITV	140V VBATT	130V VBATT	2X3w/5w AUDIO	2X1w AUDIO	1X1w AUDIO	2X2w AUDIO	INDIA SVBW006ER
		YES	YES		YES
					、				T1.0A	T1.0A
								T2.5A			T2.5A	T2.5A
		YES		YES
1	330/400V	330/400V	220/450V	330/450V	220/400V
	1000u	3300u	3300u	33000
								2200/25V			2200/25V	2200/25V

									1000/16V	1000/16V
, \|	220V/9R	220V/9P	220V/9R		220V/9R
1	VEC	LLUVIJN	VEC
	15		2R2/5u		2P2/5u
	22K / 2u	338/31	68K/3u	228/24
	NTC 2P5	NTC 2P5		NTC 205
		INTO EKO				104	158
						160K	150K
			DME 2820
1			DIII 2020			VEC
						IE S		VEO			VEC	VEC
							VEC	IEQ			ILS.	ILS
		P7Y79-020		D7V70 000
		DZX70 030		BZX79-030
	CRUCI		CRH4 II	BZX79-U30
								EGP20D
									SB140	BYV27-200		FGP20D
								EGP20D			FGP20	EGP20
								EGP20D	•		EGP20D	EGP20D
	VES
	VEQ
	TEO VEO	VEC		VEC
	TES VEC	VEG		TES VEC
	IES VEO	VEO		TES VEO
	1E2	1F2	VEC	YES	VEC
			IE0		IES				VEO	VEO
									YES	TES .

DIVERSITY TABLE FOR HORIZ

	DIVE	RSITY TABLE I	FOR ALL ITEM
	PHILIPS TUBE	HUA FEI TUBE	PHILIPS TUBE
ITEM	25"/28" BLD	25 "	25"/28" BLS
	EAST-WEST	EAST-WEST	EAST-WEST
2451	15n	15n	15n
2457	390n	390n	390n
2463	1n	1n	820p
2464
2465	9n1	9n1	9n1
2466	10n	10n	10n-
2467
2468	18n	18n	18n
2470	470p	470p	470p
2471	470n	470n	470n
2472	2u2	2u2	2u2
2473	47u	47u	47u
2475	560n	560n	510n
425 (A4)	56k	56k	56k
3452	33R	33R	33R
3453
3470	33k	33k	33k
3471	220k	220k	220k
3472	100k	100k	120k
3473	1k	1k	1k
3474	3R3	3R3	3R3
3475	3R3	3R3	3R3
3477	100R	100R	100R
3479	330R	330R	330R
3481/82	Refer to	part list	videocontrol
5445	242253102325	312813820681	242253102324

5451	33uH	33uH	33uH
5457	312813853111	312813853111	312813853111
5463
5465	312813834011	312813834011	312813834011
5470	311233830531	311233830531	311233830531
. 5471
5480	33uH	56uH	33uH
6461	BYW95C/20	BYW95C/20	BYW95C/20
6470	BZX79-C9V1	BZX79-C9V1	BZX79-C9V1
6471	1N4148	1N4148	1N4148
6472	1N4148	1N4148	1N4148
6473	BZX79-C39	BZX79-C39	BZX79-C39
7470	STP16NE	STP16NE	STP16NE
9453	YES	YES	YES
9460
9461
9462	YES	YES	YES
9463
9464	YES	YES	YES
	l	l	l


3	4	5	6	7	8	9

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6			7		8		9		10		11
					D	IVERSITY	TABLE FO	DR HORIZ	ONTAL DI	EFLECTIO	N
						DIVE	RSITY TABLE	FOR ALL ITEM	NO. MARKED	WITH *
(3w/5w UDIO	2X1w AUDIO	1X1w AUDIO	2X2w AUDIO	INDIA SVBW006ER	ITEM	PHILIPS TUBE 25"/28" BLD EAST-WEST	HUA FEI TUBE 25" \| EAST-WEST	PHILIPS TUBE 25"/28" BLS EAST-WEST	PHILIPS TUBE 25V (26") NO EAST-WEST	27V (29") NO EAST-WEST	27V (29") EAST-WEST
					2451	15n	15n	15n	15n	15n	15n/ t2n Chune
	T1.0A	T1.0A			2457	390n	390n	390n	390n	390n	360n
2.5A			T2.5A	T2.5A	2463	In	1n	820p	470p	680p	820p/th Chine
					2464						202
					2465	9n1	9n1	9n1	10n	l⊎n '	IUn
					2466	10n	10n	10n
00/25V			2200/25V	2200/25V	2467						22n
	•				2468	18n	18n	18n			33N 470-
	1000/16V	1000/16V			2470	470p	470p	4/0p			470p
\|					2471	470n	470n	1/0n			2.12
	•				2472	2u2	202	2u2 47			202 47u
					24/3	4/0	4/U	F10*
					24/5	560n	1 560n	5100	15.01.	1204	150k
					425 (A4)	55K	20D	56K	150K	228	228
					3452	33K	JJK	335	4P7	427	X
					3453	226	334	334			33k
					3470	220L	2204	2204
					3471	220K	220K	1204			82k
YES			YES	YES	3472		1000	14			1k
					2474	303	323	383			4R7
					37/7	583	J JNJ		1	1

33uH 27uH | 27uH | 27uH 312813853111 312813853111 312813853241 5465 56uH 33uH BYW95C/20 BYW95C/20 1N4148 BZX79-C39 STP16NF STP16NE STP16NE 9460 YES

100R

330R

100R

330R

EGP20

100R

330R

Refer to part list videocontrol Depends on country

242253102325 312813820681242253102324242253102326242253102326

CL 86532104_048.eps 020399

100R

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5006 D6 5201 C11 5202 E9 5821 C11 6003 C4 6004 C4 6005 B6 6006 B6 6007 D3 6008 A3 6701 F2 6702 G2 77000 B7 7001 H4 7250 A E 7251 C10 7252 F8 7253 F9 7254 D10 7256 D9 7266 E7 77701 G2 7702 H3 9000 B6 9002 A6

7701 G2 7702 H3 9000 B6 9002 A6 9003 D3 9004 F3 9005 C10

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4601 D4

M24 A

9600 D4 32 B1

607-I C4 3607-J C4 3608-C E4

09-F C7

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	12000000 12200000 12200000 15577800 155800
	100000220001112770000 1000002200011112770000 10000220202020202020202020202020202
•	10000000000000000000000000000000000000
	222222222222222222222222222222222222222
	14444445000000-1- 144444450000000-1- 20202222222222222222222222222
•	1113034444005 22222222222222222222222222222222

MAIN-MAPT. eps 260299

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2955 B6 2958 C5 2960 A8 2961 D5 3950 D3

3957 B4 3958 B5 3959 C5 7951 C7

9960 E3

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C DBX

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0215 D 0232 B

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CL 86532104_016.eps 030399

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General: the Service Default Mode (SDM) and Service Alignment Mode (SAM) are described in chapter 5.

8.1 Alignment conditions

All electrical adjustments should be performed under the following conditions:

Supply voltage : 220V 240V (10%) for 230V sets and 100V - 110V (10%) for 110V sets.
Warm-up time: 10 minutes
The voltages and oscillograms are measured in relation to the tuner earth.
Test probe: Ri > 10MΩ Ci < 2,5 pF.</li>
8.1.1 Selection of the SDM-menu
- By transmitting the "DEFAULT" command with the RC7150 Dealer Service Tool (this works both while the set is in normal operation mode or in the SAM)
- Standard RC sequence 062596 ( within OSD time-out ) MENU
- By connecting test-point M25 and M24 together on the mono-carrier while switching on the set. After switching on the set connection can be removed. (Caution!! This also overrides all the 5V protections.
8.1.2 Selection of the SAM-menu
- By transmitting the "ALIGN" command with the RC7150 Dealer Service Tool
- By pressing the "CHANNEL DOWN" and "VOLUME DOWN" key on the local keyboard simultaneously when the set is in SDM
- Standard RC sequence 062596 ( within OSD time-out ) OSD
- By connecting together test-points M28 and M29 on the mono-carrier while switching on the set. After switching on the set the short-circuit can be removed. ( Caution!! Overrides 5V protections ).

8.2 Electrical Alignments

8.2.1 VG2

Use a pattern generator to display a blank raster.
Program the pattern generator with a frequency of 475.25 MHz for PAL/SECAM or 61.25 MHz for NTSC.
Switch on the TV set.
Select the SDM-MENU. The tuner is set to a frequency of 475.25 MHz for PAL/SECAM or 61.25 MHz for NTSC.
Select the" SAM-MENU".
Press the "MENU" key on the RC to leave the SAM-MENU and go to the normal user menu ( "SAM" remains displayed at the top of the screen). Select with the MENU UP/DOWN command the sub-menu BRIGHTNESS. Change the default value from 31 to 50 with the MENU LEFT/RIGHT keys. Select the CONTRAST sub-menu and change the value from 31 to 0.
Leave the normal user menu to return to the SAM-MENU, by pressing the MENU key on the RC.
Select sub-menu VSB and change the value from 0 to 1 by pressing the MENU LEFT key. CAUTION!! Depending on the position of the VG2 potentiometer, the raster will turn completely black because the Vertical deflection stage has been disabled.
Adjust with VG2 potentiometer (located on the LOT 5445) so that the blue line in the middle of the screen is only just visible.

• The VG2 adjustment has now been completed; Switch the set to Standby. The values used for the BRIGHTNESSand the CONTRAST-during the alignment, will revert back to their original values.

8.2.2 Focusing

Set the pattern generator (e.g. PM5418) so that the Circle and Small Squares pattern is visible. Connect via the RF input with an RF signal amplitude of 10mv. Adjust focus potentiometer (positioned on the LOT 5445) for maximum sharpness of the picture.

8.3 SOFTWARE ADJUSTMENT

8.3.1 Geometry adjustments
- Set the pattern generator (e.g. PM5418) so that the Circle and Small Squares pattern is visible. Use an R.F frequency of 475.25 MHz for PAL/SECAM and connect the generator to the RF input. Use a signal amplitude of -10mV, France select L'-signal.
- First enter the SDM mode to set the tuner at 475.25 MHz.
- Enter the SAM mode and then select GEOMETRY with the up/down keys buttons on the RC, the respective items can now be selected. Use the left/right buttons to adjust the selected items so that the correct the picture geometry is achieved.

Vertical Amplitude and Position

Select Vertical Slope "VSL" and shift the test pattern to the top. The text VSL and its value should be above the upper half of the screen
Select Service Blanking "SBL" and set it to 1. The lower half of the picture will be blanked.
Press the up button once to select Vertical Slope "VSL". Now align "VSL" to start the blanking exactly at the horizontal white line at the centre of the test circle. "VSL" has the correct value now and should not be adjusted any further.
Press the down button once to select "SBL" and set it back to 0. The full picture now reappears.
Now select Vertical Amplitude "VAM" and align the picture height to the top of the screen, so that the top horizontal line just disappears. This corresponds with an over scan of approx. 6%.
Select Vertical Shift "VSH" and align for vertical centring of the picture on the screen.
Repeat the last two steps if necessary.

Select Vertical S-correction "VSC" to align the top/bottom squares till they have the same size as the squares in the middle of the screen.

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take affect after the set has been switched OFF and ON with the mains switch (cold start).

The following options in SDM can be identified:

L9.1A

OP	OPTION (ON=enabled / present). Explanation / Remark
AC	Alternate Channel. Alternate channel function (SWAP between last presets) enabled
АМ	Animated Menu
2X	External 2AS. Autostart up/Micro controller start up Default value is On (ON = start up via micro controller, OFF = auto start up BIMOS
ВМ	Blue mute (ON = enabled). Enabled: blue mute background in case of no video ident/poor signal conditionsBSBIMOS standby mode Default value = ON
BL	Balance . Enabled: menu item BALANCE available
BT	Bass/Treble Control. Menu controls for BASS and TREBLE available when enabled
СН	Child lock. Menu item Child lock when enabled
СК	Clock (Volatile). Clock function available when enabled
CL	Child Lock. Menu item Child Lock/Parental control when enabled
СР	Contrast Plus. Menu item Contrast Plus available when enabled
сх	16:9 Compress. Menu item 16:9 compress when enabled
DM	Demo Mode Demonstration of TV functions on screen when enabled
DU	Dual I/II. Possibility of language selection when enabled
EW	East-West Control. East-West Alignment in SAM GEOMETRY menu available when enabled
EX	4:3 Expand. 4:3 expand mode available when enabled
FQ	Frequency display. Frequency displayed when enabled
HS	Hospital Mode. Possibility to block the local keyboard when enabled
IS	Incredible Surround. Incredible surround function available when enabled
MS	Message . Menu item Message when enabled
NI	No Ident Auto Standby . Set switches to standby after 10min. when NI enabled
NR	Noise Reduction . Menu item Noise Reduction when enabled
RC (*)	Separate preset/volume control on remote control (ON = separate control (A8 RC); OFF = combined control (L7 RC))See note below table. Default value is OFF

SA	Spatial (Incredible stereo). Menu item Incredible Stereo when enabled
SB	Sound Board (Set the sound hardware configuration)
÷	MA = Mono All
	60= Mono All with stereo playback
	MM= Multi Mono
	IT = 2CS stereo processor MSP3400 (German or Korean stereo)
	NB = Nicam/2CS processor MSP3410B
	ND = Nicam/2CS processor MSP3410D
SP	Smart Picture. Smart picture command is processed when enabled
SS	Smart Sound. Smart sound command is processed when enabled
ST	Sound systems supported
	SS = BG, I, DK, M
	AD = BG/I, BG/DK, I/DK
SY	Systems supported
	SS = Single system
	AD = AP Dual
	AM = AP-Multi
	AF = AP-Full Multi
TN	Tuner (OFF: Philips tuner, ON: ALPS tuner) Default value = OFF
TW	Channel Select Time Window (OFF: 2 seconds, ON: 5 seconds) Time interval for entering a second digit for channel selection
UB	Ultra Bass. Ultra bass function available when enabled
VI	Virgin ModeOSD at very first installation when enabled

(*) Remark: When the option RC = OFF, the P+ and the P- key on the remote control have the same functions as the MENU UP/DOWN keys while the VOL+ and the VOL- key have the same function as the MENU LEFT/RIGHT keys. When RC=OFF, it is not possible to change the channel pre set or to adjust the volume in SAM/SDM with the remote control.

RC = OFF for use with L7-based remote control (only cursor keys). RC = ON for use with A8-based remote control (cursor keys, P+/P- and Volume+/Volume-).

8.5 Option bits/bytes

OB1 bits 8, 7, ..., 1: DP, FQ, AM, HS, HT, DM, GM, VI OB2 bits 8, 7, ..., 1: CK, CL, AT, CI, FV, HC, SS, SP OB3 bits 8, 7, ..., 1: RC, CH, (res), (res), TW, AC, SF, VM OB4 bits 8, 7, ..., 1: TN, FT, XT, 2X, XS, CD, BM, NI OB5 bits 8, 7, ..., 1: EX, CX, NR, CP, CT, EW, BS, AS

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43 Horizontal Amplitude and Phase

Select Horizontal Shift "HSH" to horizontally centre the picture on the screen

For sets with E/W correction follow the instructions below:

Select East-West Width "EWW" and align the picture with substantial over scan.
Select East-West Trapezium "EWT" and align for a rectangle if necessary
Select East-West Parabola "EWP" and align for straight vertical lines.
Select East-West Corner "EWC" and align the corners.
Repeat if necessary.
Option code "H60" and "V60" do not need any alignment. Default value H60 and V60 = 10.

To return to the main SAM-menu , press the MENU key on the RC.

To exit the SAM-menu and store the alignments in the NVM, press the STANDBY-key on the RC.

8.3.2 AGC

Set pattern generator (e.g. PM5418) with colour bar pattern and connect to aerial input with RF signal amplitude - 10mV and set frequency for PAL/SECAM to 475.25 MHz. For France select the L'-signal.

Select the" SAM-MENU".
Select the TUNER sub-menu and select the AFW option. Set this to a value of 80kHz.
Select the AGC subsub-menu
Connect a DC multi-meter to pin 1 of the tuner IC 1000.
Adjusting the AGC until the voltage at pin 1 of the tuner is 1.0V +/- 0.1V.
The value can be incremented or decremented by pressing the right/left MENU-button on the RC.
Switch the set to standby.

8.3.3 IF-PLL

Connect a pattern generator (e.g. PM5418) and select colour bar pattern and connect to the aerial input with RF signal amplitude of 10mV and set frequency to 475.25 MHz for PAL/ SECAM or 61.25 MHz for NTSC.

Select the " SAM-MENU".
Select at the TUNER sub-menu and set the AFW at its lowest value.

For the IF-PLL option the following should be done:

Select at the TUNER menu the IF-PLL subsubmenu
Adjust the IF-PLL value until AFA becomes "1" and AFB alternates between "0" and "1"
Switch the set to Standby.

8.3.4 Tuner options CL and YD

NO ADJUSTMENTS NEEDED FOR THESE ALIGNMENTS. The default values for these option codes are:

– CL:4

- YD:12

8.3.5 White tone
- Connect a pattern generator (e.g. PM5418) and set it to colour bar and circle pattern.
- Set the frequency and output for PAL 475.25MHz with RF signal amplitude of 10mv and connect to tuner (aerial) input
- Enter the SAM -MENU.
- Enter the WHITE TONE menu and then select either NORMAL, DELTAWARM, or DELTACOOL depending on the item which needs to be aligned. Only one of the three items (R, G or B) will be displayed on the screen.

The default values for the colour temperature as displayed in the table below:

NORMAL	10500K	R = 40	G = 40	B = 40
(DELTA)COOL	14000K	R = -2	G = 0	B = 6
(DELTA)WARM	8200K	R = 2	G = 0	B = -7

Switch the set to standby.

8.3.6 Audio

NO ADJUSTMENTS NEEDED FOR SOUND.

The default values for the audio alignments, with option code ND for the soundboard option "SB" - the most extended version, are displayed in the table below:

AUDIO Alignment Options
A-FM	232
AT	4
STEREO	15
DUAL	15

The presence of an item in the menu is dependent on the selected soundboard (option SB).

8.4 Options

Options are used to control the presence / absence of certain features and hardware. There are two ways to change the option settings. The various option configurations and the descriptions of the two character-codes are explained below.

Changing a single option:

A single option can be selected with the MENU UP/DOWN keys and its setting can be changed with the MENU LEFT/ RIGHT keys.

Changing multiple options by changing option byte values:

Option bytes make it possible to align very all the options. An option byte represents a number of different options. All options applicable to the L9 are controlled via 7 option bytes. Select the option byte (OB1, OB2, OB3, OB4, OB5, OB6 or OB7) and key in the new value.

Changes in the options and option bytes settings are saved when the set is switched to standby. Some changes will only

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46 L9.1A

Circuit description new circuits

Power supply (diagram A1)

9.1 Introduction

9.1.1 General

The switch mode power supply (SMPS) is mains isolated. The control IC7520 (MC44603A) produces pulses for driving FET 7518. Power supply regulation is achieved by using duty cycle control at a fixed frequency of nominal 40 kHz in normal operation. In stand-by, slow-start and overload situations the SMPS runs at frequencies other than 40 kHz.

Basic characteristics of this SMPS :

Mains Isolated flyback Converter type
Input range : 90 276 Volts AC
Secondary Sensing by Opto-coupler
IC7520 is Featured with Slow-Start circuitry
Protection Circuits
Degaussing circuit

9.1.2 Output voltages

Audio Supply (+16.5V) for the AUDIO AMPLIFIER ( Diagram A12)
Mains Supply (+140V) for the HORIZONTAL DEFLECTION stage (A2) and the CRT discharge circuit (A3)
Vaux (+11.3V) for the Video IF (A5), Video processing (A6) and Control circuit (A7)

9.1.3 The switching periods of TS7518

The power supply duty cycle is dependent on the T-on of FET 7518. The FET is driven by pin 3 of IC7520. This IC controls the secondary voltage (VBATT via opto-coupler 7581 and regulator 7570. The switching period of TS7518 can be divided into three main phases: Duty cycle T-on, T-off and T-dead.

During T-on, FET 7518 conducts.
Energy is stored in the primary winding (2-5) of transformer T5545 by using a linear increasing primary current. The slope depends on the rectified mains-voltage present across C2508. The T-on period is varied to provide regulation of the drive waveform at pin 3 of IC7520. By controlling the duty cycle of the SMPS in this way the (VBATT is controlled.
During T-off, FET 7518 is switched off and therefore does not conduct. The energy is now transferred to the secondary side of the transformer and then supplied to the load via the secondary diodes (D6550, D6560 and D6570,D6590). The current through the secondary side of the transformer decreases until it reaches zero.
During T-dead FET 7518 does not conduct. The voltage at the drain of the FET decays and eventually reaches the input voltage of approximately 300V.

9.2 Primary side

9.2.1 Mains input and degaussing
- Mains voltage: this voltage is filtered by L5500 and L5502, rectified by a diode bridge rectifier 6505 and then smoothed by C2508 which provides a DC input voltage of 300V DC for an ac input voltage of 230V.
- Degaussing : R3503 is a PTC. When switching "on" the set, the PTC is cold and has a low-ohmic value. Relay 1580 is activated while the Reset signal, coming from the (P is
- present. This allows a very high degaussing current at

initial power on. The PTC will then heat up due to the high current involved and becomes high-ohmic which reduces the degaussing-current. During normal operation, the degaussing current is zero, because relay 1580 is open due to the absence of the (P - Reset signal.

9.2.2 Start up and take over

Start-up : The start-up circuitry consisting of 3510, 3530 and 3529 use the voltage coming from the 230V AC mains to start-up IC7520 via the supply pin 1. The output drive waveform (pin 3) is blocked by using the ICs internal logic until the voltage on pin 1 reaches 14.5 Volts however with less than 14.5 volts on Pin 1 the IC only consumes 0.3mA. Once pin 1 reaches the 14.5 Volts threshold, IC7520 will start up (FET 7518 will conduct) and pin 1 sinks a typical supply current of about 17 mA. This supply current cannot be delivered by the start-up circuitry, so a take-over circuit must be present. If take-over does not occur then the voltage on pin 1 will decrease below 9V and IC7520 will switch off. The supply begins a new Start-up cycle, see top of this paragraph. This cycle will repeat itself and can be noticed by an audible hick-up sounding noise.
Take for IC7520: During start-up a voltage across winding 8 - 9 is gradually built up. At the moment the voltage across winding 8 - 9 reaches approx. (14.5 Volts, D6540 start conducting and takes over the supply voltage Vpin 1 of IC7520 (take over current is approx. 17mA).

Note: This power supply is a SMPS (= Switched Mode Power Supply) and not a SOPS (= Self Oscillating Power Supply).

9.3 Control circuitry

9.3.1 IC7520 control mechanisms

IC7520 controls the T-on time of FET 7518 in four different ways:

"Secondary-output-sensing" controls the secondary output voltages via the feedback voltage pin 14
"Primary current sensing" control due to the mains voltage via the current sense voltage pin 7
"Demagnetization control" prevents the transformer T5545 from going into saturation via the so-called "DEMAG" function at pin 8
Mains voltage control via R3514 and R3516
9.3.2 Secondary voltage sensing (pin 14 of IC7520)

When the output voltage +VBATT increases (due to a reduction in the load ) the current through the led in the optocoupler 7581 will increase due to the fact that the seriesresistor in regulator 7570 decreases. An increase in optocoupler led-current (7581) results in a decrease in the Vce of transistor 7581, therefore the voltage across capacitor 2576 increases. This will reduce the on-time of FET 7518 due to an increase of the voltage present on pin 14.

In the event of an increase of the load (decrease of output voltage +VBATT), the control circuit will work in the opposite way to the explanation above.

9.3.3 Primary sensing (pin 7 of IC7520)

The current sense voltage at pin 7 is used to measure the primary current through FET7518. The primary current is converted into a voltage by R3518. R3514. 3516. couples a part of the main voltage to the same pin 7 of IC 7520 by dividing this sample of the voltage.

Page 86

OB6 bits 8, 7, ..., 1: BT, IS, VL, DV, UB, LV, DU, AO OB7 bits 8, 7, ..., 1: ST, ST, SB, SY, SY, SY An option byte value is calculated in the following way: value "option bit 1" x 1 = value "option bit 2" x 2 = value "option bit 3" x 4 = value "option bit 3" x 4 = value "option bit 5" x 16 = value "option bit 6" x 32 = value "option bit 7" x 64 = value "option bit 8" x 128 =

Total : value "option byte" =

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48 L9.1A

A

Circuit description new circuits

The video IF output is present at pin 11 of the tuner 1000. This signal goes through a sound SAW filter and is fed to the BIMOS via pins 48 and 49, where the signal is demodulated. . At pin 6 of BIMOS IC 7250-A, the CVBS + SIF signal is fed to another SAW filter. Signal P3Duall/Mono selects either SAW filter 1001 or SAW filter 1002.

The system hardware configuration, option code SY, is set at AD - Dual Mono for a Dual configuration, while option code SY is set at SS for the Mono configuration (BG,I, DK, M). Via P3Duall/Mono, a signal coming from the Micro-processor IC7600, it possible to switch between two Mono configurations (BG/DK or BG/I or DK/I).

This signal goes back to pin 1 of the BIMOS , for further demodulation. The demodulated FM signal or the REAR I/O audio signal, ExtAudioMono at pin 2, is switched by the BIMOS and is present at pin 15.

The signal at pin 15 is fed to pin 55 of IC 7833 - BSP3501C - at panel A10 . IC 7833 performs source selection as well as audio processing such as volume, bas, treble, balance, tone control and spatial stereo. The audio output from IC 7833, pin 28 and pin 29, is fed to the power amplifier IC 7950 or IC7951. Pin 36 and 37 pass the same selected signal through to the Audio-cinches.

Signal P10MuteVolume enables the output of the sound amplifier.

9.4.2 NICAM

This high quality digital audio format is used in Eastern Europe, France, and UK, while NICAM LL' is being used in France. The figure below shows the AUDIO path for NICAM..

Figure 9-2: "NICAM"

The video IF output is present at pin 11 of the tuner. Signal P2LIpMono is used to switch between NICAM L or L'. Depending on the required Tuner frequency band, the appropriate SAW filter is selected. The filtered signal is fed to SIF (sound I.F amplifier) input pin 55 and 56 of the BIMOS - TDA8845. Output pin 15 - AM Audio output-, is connected to ground via jumper 4002.

The QSS signal at pin 2 passes through the selected high pass filter, depending on the system used, and is fed to sound processor 7833. Audio signals coming from the rear I/O panel are connected to pin 49/50 of IC7833 for the Ext1 Audio signals, while pin 52/53 of IC 7833 are used for the Ext2 Audio signals.

The QSS-signal, Ext1Audio or Ext2Audio is switched internally to the output pins 28 and 29 of the sound processor. Pin 36 and 37 pass the same selected signal through to the audio-cinches.

The audio output of the MSP3415 is fed to the power amplifier IC 7950 or IC7951. Signal P10MuteVolume enables the output of the sound amplifier.

9.4.3 2CS

This analogue F.M stereo audio standard is predominately used in Germany and The Netherlands. It is used on some cable television networks. The diagram below indicates the AUDIO path for 2CS.

The CVBS + SIF signals present at pin 6 from BIMOS, -TDA8844-, are passed through a high pass filter and are then fed back into pin 58 of IC 7833 (MSP3415D) for further demodulation. All variants of 2CS are demodulated in this IC.

Audio signals coming from the rear I/O panel are connected to pin 49/50 of IC7833 for the Ext1Audio signals, while pin 52/53 of IC 7833 are used for the Ext2Audio signals. IC 7833 performs source selection as well as audio processing such as volume, balance, tone control, mute, spatial stereo, incredible surround sound and SMART sound. The audio output from IC 7833, pin 28 and pin 29, is fed to the power amplifier IC 7950 or IC7951. Pin 36 and 37 pass the same selected signal through to the audio-cinches. Signal P10MuteVolume enables the output of the sound amplifier.

9.4.4 BTSC DBX

The CVBS + SIF signals from the BIMOS are passed through a high pass filter and are then fed back into pin 58 of IC 7833 (MSP3435G) for further demodulation. This signal is present at pin 2 of BIMOS -TDA8845- for NICAM L and present at pin 6 of BIMOS - TDA8844 - for all other NICAM/2CS applications.

Figure 9-4: "BTSC DBX"

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9 Circuit description new circuits

Hence the higher the input voltage the more the primary current is limited. In this way the maximum output power of the power-supply is limited.

9.3.4 Demagnetization control (pin 8 of IC7520)

Winding 8 - 9 has the same polarity as the secondary winding that supplies the load. When FET 7518 is turned off the voltage at winding 9 becomes positive. The power supply transfers the stored energy at the secondary side. Until the transformer is demagnetized the voltage on the winding remains positive. At the moment that the energy is fully transferred to the load, the voltage at pin 9 of the transformer becomes negative. Additionally with a certain dead time the voltage at control pin 8 of IC 7520 also drops below zero which releases the output buffer (pin 3) and a new cycle starts.

9.3.5 Peak current limiting

An internal clamp at pin 7 allows peak current limiting to be achieved . This pin can never exceed 1V DC and so the maximum primary current through FET 7518, and also the maximum output power is determined. In case of an output being short-circuited or loaded excessively, the I-prim becomes too high which is detected by pin 7. As a result the primary current is limited to its maximum value and the secondary voltages will drop. The voltage at pin 1, which is coupled with the output voltage, will also drop. When the voltage at pin 1 drops below the 9V, IC7520 will stop functioning and the output voltage will rapidly drop to zero.

Via start-up circuitry 3510, 3530 and 3529 the voltage originating from the 230V AC mains is used to start-up IC7520 via the supply pin 1. As soon as this voltage reaches the 14.5V, IC7520 starts functioning. If the load is still too much or the output is short-circuited the same cycle will happen again. This fault condition can be clearly identified as the power supply will be loudly tripping.

9.3.6 Slow-start

As soon as Vpin 1 > 14.5V the SMPS will start-up. During the slow-start procedure both the frequency and the duty cycle will be built up slowly. The duty cycle will initially slowly increase commencing with the absolute lowest possible duty cycle. The maximum duty cycle is determined by C2530 at pin 11 of IC7520, as C2530 is uncharged at start-up.

9.3.7 Standby mode

In standby mode the SMPS switches to the so-called "reduced frequency mode" and runs at about 20 kHz. During standby the SMPS only has to deliver a minimal level of output power. The minimal load threshold level is determined by R3532 at pin 12. In the L9 chassis the SMPS does not have a burst mode in standby but only a reduced frequency mode of about 20 kHz as stated above. In normal operation mode the internal oscillator is around 40 kHz. This frequency is controlled by C2531 at pin 10 of IC7520 and by R3537 at pin 16 of IC7520. In standby mode the frequency of operation is determined by R3536 at pin 15 of IC7520.

9.3.8 Protections

Over voltage protection of the secondary voltages.

After start-up the supply voltage pin 1 will be "taken over" by winding 8 - 9. Pin 1 of IC 7520 is used to detect an over voltage situation on the secondary side of the transformer. If this voltage exceeds 17V (typically the output buffer is disabled, and IC 7520 goes into over voltage protection and a complete

restart sequence is required. Check in this case IC7520, IC7581 and the secondary voltage +VBATT (+140V).

REMARK: In the event of the over voltage situation remaining present, the SMPS will go in protection, start up cycle, protection, etc. The standby led on the front of the set starts flashing.

Under voltage protection of the secondary voltages

If the supply voltage at pin 1 of IC 7520 drops below 9V because of a short-circuit or excessive load, the drive pulse present at pin 3 will be disabled and IC7520 will switch off the complete SMPS. Capacitor C2450 is charged up via start-up resistors 3510, 3530 and 3529, however once the voltage exceeds 14.5V start up threshold, the SMPS will once again commence a re start cycle.

In the event of the under voltage situation remaining, the SMPS will again go in protection mode, start up cycle, protection, etc. and so the cycle repeats. This effect is highly audible.

9.4 Audio processing

The following systems are available:

BASIC : MONO/AV STEREO (M,BG, I and DK : single or dual system)
NICAM : FM STEREO / NICAM L/L', NICAM I, NICAM B/G, NICAM DK
2CS : FM STEREO / FM MONO ( all standards 4.5, 5.5, 6.5 MHz )
BTSC : MONO/STEREO/STEREO-AP

MONO/AV STEREO, BTSC DBX incorporating 2CS (two carrier stereo) use a TDA8844/43 BIMOS device (built-in Mono FM Demodulator circuit).

NICAM LL', /BG, /I versions use a TDA8845 BIMOS (AM sound demodulator & QSS-IF circuit ; built-in)

The Audio Module incorporates for each system a different multi digital sound processor.

MONO /AV STEREO: BSP3501 & TDA884x
NICAM / 2CS : MSP3415D
BTSC : MSP3535G

These IC's have an incorporate digital audio processing for volume, bass, treble, balance, mute, spatial sound, incredible sound, smart sound and source selection (SIF-signal, EXT1 or EXT2).

9.4.1 MONO / AV STEREO

This set does have the digital sound processor BSP3501, IC7833.

MONO/AV STEREO

Figure 9-1: "MONO / AV STEREO SETS"

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L9.1A 9

Circuit description new circuits

transistor 7266 to the sound trap filters and then on to the video source selection circuit.

The main functions of the video IF part are (see also figure 9.5):

IF- amplifier
PLL-demodulator
Video buffer
AFC
IF-AGC
Tuner AGC
9.5.5 IF- amplifier

The IF-amplifier incorporates symmetrical inputs (pins 48 and 49). By using IIC bus control (IFS) the AGC attenuation can be adjusted by up to -20db.

Remark: If the BIMOS is replaced the AGC value should be adjusted as part of the repair process. (see software alignment adjustments).

9.5.6 PLL-demodulator

The IF-signal is demodulated with the assistance of the PLL detector. The video IF-demodulator can handle both negative and positively modulated IF signals; selection is achieved via the IIC bus (bit MOD).

9.5.7 Video buffer

The video buffer is present to provide a low ohmic video output with the required signal amplitude. Additionally, it provides protection against (pin 6) the occurrence of noise peaks. The video buffer stage also contains a level shifter and a gain stage for both the positive and negative video modulation formats, so that the correct video amplitude and DC level are always present at pin 6 regardless of the input signal.

9.5.8 Video-IF AGC

An AGC system controls the gain of the IF amplifier such that the video output amplitude is constant. The demodulated video signal is supplied, via a low pass filter inside the IC to an AGC detector. External AGC de coupling is provided by capacitor 2201 at pin 53. The AGC detector voltage directly controls the IF amplification stages.

9.5.9 The tuner AGC

Tuner AGC is provided to reduce the tuner gain and thus the tuner output voltage when receiving to strong RF signal. The tuner AGC starts working when the video-IF input reaches a certain input level. This level can be adjusted via the IIC bus. The tuner AGC signal is applied to the tuner via the open collector output pin 54 of the BIMOS.

9.5.10 AFC

The AFC output information is available for search tuning. The AFC output is available via the I2C bus (AFA and AFB signals). For alignment purposes it is displayed in the TUNER submenu of the SAM (See chapter 8).

9.6 Video Signal Processing (see circuit diagram A6)

9.6.1 Introduction:

The video signal processing can be divided in the following parts:

CVBS/Y/C input selection
Luminance and chrominance signal processing
PAL/NTSC and SECAM demodulation /Auto system manager
YUV/RGB processing/ black stretcher
Second RGB insertion
RGB processing
Black current calibration loop
Beaming current limiting

Above mentioned processing circuits are integrated in the TVprocessor (parts B and C). The surrounding components are for the adaptation of the selected application. The I2C bus is used for defining and controlling the signals.

Figure 9-6: "Videopath"

9.6.2 CVBS/Y/C selection

The input switches are used for selection of the input signal. Three input signals can be selected:

Pin 13: terrestrial CVBS input
Pin 17: external AV1 input.
Pin10/11: external AV2-Y, CVBS/C input

When pin 11 is in the CVBS input mode then pin 10 is not used. When pin 11 is in the Y/C input mode then both pins are used and the CHROMA filter in the Y signal path is switched off.

9.6.3 Luminance / Chroma signal processing

Once the signal source has been selected, CHROMA filter calibration is performed. The received colour burst-sub-carrier frequency is used for the calibration. Correspondingly, the CHROMA band-pass filter for PAL/NTSC processing or the cloche filter for SECAM processing is switched on. Pins 34, 35 have the crystals connected to them. These crystals are used for multi-purpose calibration of the burst sub-carrier. The selected luminance signal is then supplied to the Horizontal and Vertical synchronisation processing circuits and to the luminance processing circuits. In the Luminance processing block, the luminance signal is applied to the CHROMA trap. This trap is switched on or off depending upon on the colour burst detection of the CHROMA calibration circuit. Before the luminance signal is applied to pin 28 of the TV-processor the signal is applied to a "peaking" and "coring" circuit. In these

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9 Circuit description new circuits

9.5 Tuner and Video IF (see circuit diagram A5)

9.5.1 Introduction:

In Figure 9.4 a simplified block diagram of the video path is shown. The main item in the block diagram shown in Fig.9.5 is the video processor item 7250. The IC performs the following functions, video IF demodulation, chroma processing and RGB processing. Additionally synchronisation processing, mono IF audio demodulation and audio selection takes place.

Two versions of video processors are used:

TDA8844 N2 for SW CENELEC BG/DK, CENELEC I NICAM, CENELEC BG NICAM
TDA8845 N1 for CENELEC BG,LL',I

For a detailed block diagram of the TDA8844/8845 see Figure 9.5.

Figure 9-5 :Bimos

9.5.2 Tuner

The PLL tuner (item 1000) is digitally controlled via the I2Cbus. The tuner is suitable to receive off-air, S-(cable) and hyper band channels.

Tuner pin description:

Pin 1: AGC, Automatic gain control voltage input (0.3 -4.0V)
Pin 2: VT, tuning voltage input (not connected)
Pin 3: AS, address select (not connected)
Pin 4: SCL, IIC-bus serial clock
Pin 5: SDA, IIC-bus serial data
Pin 6: not connected
Pin 7: Vs, PLL supply voltage +5V
Pin 8: not connected
Pin 9: Vst, tuning voltage +33V
Pin 10: ground
Pin 11: IF, asymmetrical IF output

Note: The +5V supply voltage and the +33V tuning voltage is derived from the line output stage, see diagram A2).

9.5.3 IF band pass filter (SAW FILTER)

Between the tuner output and the video IF input of the video processor the IF band pass filtering take place. Filter 5002 is tuned at 40.4MHz and serves as an extra suppression of the neighbour channel. For the IF band pass filtering SAW filters are used (item 1003 or 1004). 5 Types of SAW filters are used depending of the version of the set.

9.5.4 Video IF

General: Video IF-demodulation is achieved in combination with reference circuit L5006 connected at pin 3 and 4 of IC7250-A. The AGC control for the tuner is applied via pin 54 of IC7250-A. Internally the IC uses the top sync level as a reference for AGC control. The AGC adjustment can be readjusted via the SAM (service alignment menu). C2201 connected to pin 53 determines the time constant of the AGC. The Base band CVBS signal is present at pin 6 of IC7250-A (normal amplitude 3.2Vpp). From here the signal is fed via

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4 Connecting peripheral equipment 5 ...connecting peripheral equipment Equipment such as VCR, Laser disc player, VCD etc. could be connected to Connection for recording the video and audio (AV) sockets at the back of the TV. Switch off the TV and equipment before making any connection. 1. From the TV channel you are watching Connection for playback connect the corresponding sockets of 1. Connect to AV sockets the VCR to the sockets at MONITOR out. You may choose to connect up VIDEO 1 in or VIDEO 2 in or both connect the corresponding sockets of the equipment to that of the TV to view the playback, select the first AV channel (if connection is made to sockets at VIDEO 1 in) or the second 2. From one VCR to another VCR AV channel (if connection is made to o connect the sockets of the VCB which sockets at VIDEO 2 in). you wish to record from to the corresponding sockets at either VIDEO Laser disc in 1 or VIDEO in 2. plaver connect the sockets of the receiving VCR to the corresponding sockets at MONITOR out 3 From the TV antenna 2 Connect to aerial socket connect the RE cable to the VCR's "RE (only for VCR) in" and the "BE out" of the VCB to the The playback on your VCR is considered a aerial socket of the TV TV channel by your TV if you connect via the aerial socket. You must tune in to your VCR's test signal and assign the channel number 0 to it. Refer to your VCR's instruction manual for more details connect the RE cable to the VCB's "RE in" and connect the "RE out" of the VCR to the aerial socket of the TV. Connection for headphones select channel 0 and tune in to to your VCR's signal. DHILDS to view the playback, select channel 0. connect the headphones to the socket at the front of the TV The headphones impedance must be between 8 and 4000 ohms.

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9 Circuit description new circuits

circuits the sharpness and noise level of the signal can be influenced via the remote control (control menu in the user menu).

9.6.4 PAL, NTSC and SECAM demodulation via the Auto system manager

The colour decoder circuit detects whether the signal is a PAL or NTSC signal. The result is made known to the auto system manager. The base-band delay line is activated when a PAL or SECAM signal is detected. For the SECAM colour standard a reference voltage is generated at pin16 of the TV-processor.

Connected at Pin 9 of the TV-processor, is the band-gap decoupling circuit, which consists of (2214,2215). The band-gap circuit provides a very stable and temperature independent reference voltage. It ensures optimal performance of the TVprocessor and is used by almost all functional blocks inside the processor. The Y signal and the demodulator outputs R-Y and B-Y are present at pin 28, 29, 30 of the TV-processor. The auto system manager identifies PAL, NTSC and SECAM colour standards and is controllable via the IIC bus. Connected on pin 36 of the TV-processor is the Loop Filter for the phase detector The filter chosen provides an optimal transient response, which ensures both an optimum for noise bandwidth and colour acquisition time.

9.6.5 YUV / RGB processing/ black stretching

The signal Y, R-Y and B-Y present on pins 27, 31, 32 of the TVprocessor are used as the input signals for the colour decoding section of the BiMOS (IC7520-C). The YUV processor enables the colour saturation control and also converts the Y, B-Y and B-Y signals to the R, G, B signal format via the colour matrix circuit. The black stretcher circuit , initial stage of the matrix circuit, extends the Grey signal level towards the actual black level. The amount of extension depends upon the difference between actual black level and the darkest part of the incoming video signal level. This feature is fully integrated. The user can switch this circuit on or off by using the Contrast Plus option in the user menu.

9.6.6 Second RGB insertion

Pins 23, 24, 25 are used as the inputs for the second R, G, B signals insertion. Pin 26 of the TV-processor is the input for the insertion control signal which is called "FBL". When the FBL signal level becomes higher than 0.9V (but less than 3V) the R, G, B signals at pins 23,24,25 are inserted into the picture by using the internal switches incorporated in the TV-processor. This second insertion possibility is used for insertion of the on screen display signals , TXT or R. G. B signals from the CINCH socket.

9.6.7 RGB processing

The RGB processing circuit enables the picture parameters to be adjusted by using a combination of the user menus and the remote control. Additionally automatic gain control for the RGB signals via cut-off stabilisation is achieved in this functional block..

The block also inserts the cut off point "measuring pulses" into the RGB signals during vertical retrace period. From outputs 19,20 and 21 the RGB signals are then applied to the output amplifiers on the CRT panel.

9.6.8 Black current calibration loop

The black current calibration loop ensures that the white balance at low signal levels and low light white balance is

skipped. By means of the inserted measuring pulses, the black current calibration loop, tracks the beam current feed back of the RGB signals at the cathodes of the picture tube. As a result of this calibration, the individual black level of the RGB output signals is shifted to a level which allocates around 10uAof beam current to each of the RGB signals. Pin 18 (BC_info) of the BIMOS is used as the feed back input from the CRT base panel.

9.6.9 Beam current limiting

A beam current limiting circuit inside the BiMOS handles the contrast and brightness control for the RGB signals. This prevents the CRT tube being over driven, which may cause serious damage in the line output stage. The reference used for this purpose is the DC voltage on Pin 22 (BLCIN) of the TV-processor. Contrast and brightness reduction of the RGB output signals is therefore proportional to the voltage present on this pin. Contrast reduction starts when the voltage on pin 22 is lower than 3.0 V. Brightness reduction starts when the voltage on pin 22 is less than 2.0 V.

The voltage on pin 22 is normally 3.3V (limitor not active). To enable correct operation however, an external adaptation to the circuit is required for the correct functioning of the limiting function. This is connected to Pin 22, the circuit therefore ensures that correct peak white limiting and the average beam current limiting takes place. Components 6212, 2227, 3253, 3246 are for the average beam current limiting and the items connected to 7263 are for the neak white limiting. As a reference for the average beam current control the signal EHT info is used. This signal is a measurement of the picture contents. It is filtered by 3253, 2227. As the time constant of the filter is much bigger than the frame period time, the DC at the anode of 6212 represents the average value of the picture content. Via 6212 and 2226 the DC voltage at pin 22 is slowly 'clamped'. For peak white limiting transistor 7263 is utilised. When peak white occurs, the DC voltage at the base of 7263 drops rapidly. 7263 starts conducting, which provides a path to discharge the capacitor 2226 very fast. The voltage bias at the base of 7263 is fixed via voltage divider 3251 and 3249. The RGB output signals are applied to the CRT panel via connector 0243. Via diodes 6263, 6264 and 6265 and series resistor 3253, the RGB signals are also connected to the CRT discharge signal. The level of this signal is only high during the time the set is switched off. And id due to the cathodes of the CRT are driven fully negative. That means that the beam current is increased, and consequently the CRT quickly discharged.

9.6.10 CRT panel (see circuit diagram B)

On the CRT panel the output amplifiers for the RGB signals (IC T7330, DA6107Q) are located. Via the outputs 9, 8 and 7 of the IC the cathodes of the CRT are driven. The supply voltage for the IC is +200VA and is derived from the line output stage.

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3 using the	remote control
	Press: Backback	Result:
	Menu Menu	Call up the main menu. If there is an existing menu, pressing this key will bring you back to the previous level menu. If you are in the 1st level menu, pressing this will exit the menu.
	Sum Incredible Sum Surround	Switch on to enhance stereo sound from your TV.
023 066	Mute	Switch off the sound of the TV. Press again to switch on the sound.
	Channel Selection	Select a higher or lower channel number .
	Uolume adjustment ∠ ⊖	Adjust the volume of the TV set.
PHILIPS	Teletext function:	Refer to the section on "Teletext".
	COURD AVCH Surf or alternate channel	Surf mode : Add or delete channel from the surf list. View channel in the surf list. A/CH mode : Return to the previ- ous channel.
	FII Sound (17) mode	Switch from stereo to mono sound (for stereo transmission) or choose between first language or second language (for bilingual transmis- sion).

10 Directions for use

9.1A

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Enter INSTALLATION Press the Okey to Select MANUAL with highlight MANUAL . B If you wish to fine A Press the O key to tune the channel highlight FINE TUNE. Press the O or O key to fine tune 197 HHZ ►

SWAP

scroll down to

SEARCH 197 P FINE TUNE ------------------------------------

B Exit with the

kev.

...installing the tv – manual

Manual

menu.

LANGUAGE . ENGLISH Auto store

Press the key to

highlight SEARCH and

the key to start

Searching stops once

a channel is available.

SYSTEM AUTO SEARCH 197 MHZ -

Press the O key to

highlight STORE and

press the O or O

key to store the

channel.

FINE TUNE

STORE

SEARCH ....

FINE TU

searching.

This menu enables you to search and store every available channel manually.

L9.1A

.......................................

NORMAL

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Sound settings

Personal settings

You can do adjustment on TREBLE . BASS and INCREDIBLE SURROUND* of a nicture via the 1st level menu. These adjustment will automatically be stored in the PERSONAL mode of the SMART SOLIND feature

How to do adjustment

Call up 1st level menu with the exercise

• Press the $\bigwedge$ or $\bigcap$ key to highlight the item that you wish to adjust.

B Select or adjust with the O or O key.
Exit with the key.

*Switch on this feature and you will feel the incredible depth and unbelievable three-dimensional effect of stereo sound

Other sound settings Volume

Adjusts the volume level of the TV. You can also do adjustment via the buttons on the front of the TV or remote control.

Ralanco

Balances the stereo sound output of speakers in the TV

16:9 COMPRESS

______ (________)

21 Off air storen sound (only available in certain models)

If a TV programme is transmitted in NICAM* or STEREO*, you can switch to MONO and back again. When there are two languages in simultaneous transmission, you are able to select either one. (*Dependent on the sound system in transmission)

Switch to mono

Press the (1) key to switch between stereo and mono

Select first or second language Press the () key to select first or second language.

Personal preference

This built in feature of the TV automatically store the picture and sound settings that you last made to a particular channel in the PERSONAL mode of Smart Picture or Smart Sound.

Personal preference settings

Group 1 ·

For channel number 0 to 11, each channel has its own personal preference.

Group 2:

For channel number 12 to 99, one personal preference applies to all. If you make changes to the picture or sound settings of any channel in this group. this will be stored as the personal preference for all.

Group 3:

For the two AV channels, each channel has its own personal preference.

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0 Directions for use

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A/CH

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11 List of Abbreviations

P4ScartPin8/SVHS	Switching signal from I/O to micro controller with several functions:Scart1 I/O: detects
	signal type connected to Scart 1 (no signal,
	16:9 signal, 4:3 signal) (only for Europe)Cinch
	I/O: detects signal type connected to cinch:
	SVHS or CVBS (not for Europe)
P5BassSw	Bass switching signal (only for some mono
DetrobleSw	Troble switching signal (only for some mono
Forrebleow	sets)
	Lised in L9-ITV sets (Hotel TV)
Plethvon+protn	Signal from F-W and LOT output to micro
i əsibyon+proin	controller to (de)activate the protection mode
P10Mute/Volume	Audio mute / Volume control signal nin
POR/CLK	Power on reset (only used in L9-ITV sets)
R-	Power amplifier output " R- " to speaker
R+	Power amplifier output " R+ " to headphone
	and speaker
RAM	Random Access Memory
RESET	Reset signal to micro controller
RF AGC	Automatic gain control signal from BiMOS
	output to tuner input.
RGB	Red-Green-Blue
RGB_Blanking	Red Green Blue Blanking signal (combined
	with AV_MUTE)
RightOut	Audio right signal output
R_TXT_OSD	Red TXT or OSD signal from uC to the video
	controller IC7250 (BIMOS)
ROM	Read Only Memory
SAM	Service Alignment Mode. Service mode for
	alignments and error buffer display
SAP	Second audio program (only for USA & A/P
	sets)
SCL	Clock line of the I2C-bus
SCL2	2nd Clock line of the IIC-bus (only used in L9-
	IIV sets)
SDA	Data line of the I2C-bus
SDA2	2nd Data line of the I2C-bus (only used in L9-
ODM	Liv Sels) Service Default Made, Service made with
SDM	service Delaut Mode. Service mode with
	measurements, error buffer display and option
	(hyte) setting
QIE	Sound IE signal for EM audio demodulator
SMPS	Switching Mode Power Supply
STANDBY	Switching signal from micro controller: "low" for
01/11/00/	standby (power supply will be switched to
	stand-by mode), "high" for normal operation
SW OUT	Selected Output signal from source
SYNC	Synchronisation
TBD	To Be Defined
TREBLE	Control signal for treble
ТХТ	Teletext
uC	Micro controller
USA	United States; schematic/PCB information
	(only) applicable for North American sets
V_TUNE	Tuning voltage for tuner
Vdrive -	Negative Vertical drive pulse signal
Vdrive +	Positive Vertical drive pulse signal
VD	Vertical pulse derivation
VFL	Vertical flyback pulse used to inform the micro
	controller that flyback is occurring. This is
	Critical for the correct USD and TXT
	Vehical liyback pulse
VG2
VideoOut	CVRS output signal
	Control signal (from micro controller, but on
VOLUME	DC level via BC network) for sound processing
	in sound IC
XRAY-PROT	XBAY protection (only for USA sets)
YC	Luminance (Y) and Chrominance (C)