RCA DTV306, DTV307 Diagram

Television

Tech-Line Tip

TTT01-002

The information contained herein is provided solely to assist in the diagnosis of the problem described. It is not intended as a modification or alteration of the product.

DATE: 6/4/01 MODEL/CHASSIS: DTV306/307 TOPIC:Putting Chassis in Service Position

1. Remove the yoke board as shown in picture 1.

2. Remove the DM-1 power supply as shown in picture 2.

3. Swing the left end of the chassis out as shown in picture 3.

4. Turn the chassis over to get to the bottom as shown in picture 4.

Picture 1

Product Safety Information

Product Safety information is contained in the appropriate TCE Service Data covering models/chassis referenced herein. All specified Product Safety requirements and testing shall be complied with prior to returning equipment to the customer. Servicers who defeat safety features or fail to perform safety checks may be liable for any resulting damages and may expose themselves and others to possible injury.

Page 1 of 3 (TTT01-002)

Picture 2

Picture 3

Product Safety Information

Page 2 of 3 (TTT01-002)

Picture 4

Product Safety Information

Page 3 of 3 (TTT01-002)

Television

Tech-Line Tip

TTT01-006

The information contained herein is provided solely to assist in the diagnosis of the problem described. It is not intended as a modification or alteration of the product.

DATE: 8/9/01 MODEL/CHASSIS: DTV300, DTV306, and DTV307 TOPIC:

TOPIC: Troubleshoot the DM-1 SYMPTOM: No signal in the menu

If when trying to view Satellite channels you get “searching for signal” the problem may be that the 13/18 voltage coming from the DM-1 is missing. Place the unit is standby and hook a voltmeter on the satellite RF input (center is positive and outside shield is ground). Watch for the voltage to go from 13 volts to 18 volts. If the voltage is there, the problem is at the dish. You need to check the multi-switch or the LNB’s. If the voltage is not there, you need to troubleshoot the DM-1 power supply.

Product Safety Information

Page 1 of 1 (TTT01-006)

Television

Tech-Line Tip

TTT01-007

The information contained herein is provided solely to assist in the diagnosis of the problem described. It is not intended as a modification or alteration of the product.

DATE: 8/9/01 MODEL/CHASSIS: DTV306 and DVT307 TOPIC:

TOPIC: CR14608 SYMPTOM: Power light comes ON but no power

When you press the power button and the power LED stays on but you have no power, you need to check VCC on pin 16 and 29 of U13101. If the voltage is low, go to CR14608 and check for 5 volts. Upon checking the diode, if the voltage is missing, change the diode. This diode is located in the standby power supply and supplies voltage to the micro continuously.

Product Safety Information

Page 1 of 1 ()

SAFETY PRECAUTIONS

DO NOT OPERATE THIS INSTRUMENT OR PERMIT IT TO BE OPERATED WITHOUT ALL PROTECTIVE DEVICES INSTALLED AND FUNCTIONING. SERVICERS WHO DEFEAT SAFETY FEATURES OR FAIL TO PERFORM SAFETY CHECKS MAY BE LIABLE FOR ANY RESULTING DAMAGE, AND MAY EXPOSE THEMSELVES AND OTHERS TO POSSIBLE INJURY.

READ AND COMPLY WITH ALL CAUTION AND SAFETYRELATED NOTES ON OR INSIDE THE RECEIVER CABINET, AND THE RECEIVER CHASSIS, OR ON THE PICTURE TUBE.

SAFETY GLASSES SHOULD BE USED WHEN SERVICING ELECTRONIC INSTRUMENTS. INADVERTENTLY OVERSTRESSING COMPONENTS MAY CAUSE THEM TO SHATTER, DISCHARGING SMALL PARTICLES.

DESIGN ALTERATION WARNING - Do not alter or add to the

mechanical or electrical design of this TV receiver. Design alterations and additions may alter the safety characteristics of this receiver and create a hazard to the user. Design alterations or additions may void the manufacturer's warranty and may make you, the servicer, responsible for personal injury or property damage resulting therefrom.

BEFORE RETURNING AN INSTRUMENT TO THE CUSTOMER,

always make a safety check of the entire instrument, including, but not limited to, the following items:

FIRE AND SHOCK HAZARD

1. Never release a repaired unit unless all protective devices such as insulators, barriers, covers, strain reliefs and other protective hardware have been installed in accordance with the original design.

2. Be sure that there are no cabinet openings through which an adult or a child might be able to insert their fingers and contact a hazardous voltage. Such openings include, but are not limited to: (a) spacings between picture tube and cabinet mask, (b) excessively wide cabinet ventilation slots, and (c) an improperly fitted or incorrectly secured back cover.

3. Observe original lead dress. Take care to restore leads to their original dress. Make sure that leads are not in contact with sharp edges or thermally hot parts. Always inspect in all areas for pinched, out-ofplace or frayed wiring. Do not change spacing between adjacent components, or between components and printed-circuit board. Check AC power cord for damage.

4. Be certain to remove loose solder balls and all other loose foreign particles.

5. Check components, parts and/or wiring for physical evidence of damage, overheating or deterioration, and replace if necessary. Determine the cause of damage and/or overheating and, if necessary, take corrective action to remove any potential safety hazard.

6. Parts Replacement - Many TV electrical and mechanical parts have special safety-related characteristics, some of which are often not evident from visual inspection, and the protection they give cannot necessarily be obtained by replacing them with components rated for higher voltage, wattage, etc. Parts that have special safety characteristics are identified in this service data by a ( ) on schematics and in the parts list. Use of a substitute replacement that does not have the same safety characteristics as the recommended replacement part in the service data parts list may create shock, fire and/or other hazards. Always consult the appropriate current service literature for the latest information.

7. Some TV receiver chassis' normally have 85VAC (RMS) between chassis and earth ground, regardless of the AC plug polarity. Some TV receiver chassis' are electrically connected directly to one conductor of the AC power cord. Some TV receiver chassis' have a secondary ground system in addition to the main chassis ground. This secondary ground system is not isolated from the AC power line. The two ground systems are electrically separated by insulating material that must not be defeated or altered. Thus, when servicing any unit always use a separate isolation transformer for the chassis. Failure to use a separate isolation transformer may expose the servicer to possible shock hazard, and may cause damage to servicing instruments.

8. Many electronic products use a polarized AC line cord (one wide pin on the plug). Defeating this safety feature may create a potential hazard to the servicer and the user. Extension cords which do not incorporate the polarizing feature should never be used.

PICTURE TUBE IMPLOSION WARNING - The picture tube in this receiver employs integral implosion protection. For continued implosion protection, replace the picture tube only with one of the same type number.

Do not remove, install, or otherwise handle the picture tube in any manner without first putting on shatterproof goggles equipped with side shields. People not so equipped must be kept safely away while picture tubes are handled. Keep the picture tube away from your body. Do not handle the picture tube by its neck. Some "in-line" picture tubes are equipped with a permanently attached deflection yoke; because of potential hazard, do not try to remove such "permanently attached" yokes from the picture tube.

X-RADIATION AND HIGH VOLTAGE LIMITS - Because the picture tube is the primary source of X-radiation in solid-state TV receivers, it is specially constructed to prohibit X-radiation emissions. For continued Xradiation protection, a replacement picture tube must be the same type as the original. The picture shields, mounting hardware and lenses (projection TV) may also perform an X-radiation protection function, and they must be correctly in place. Anode connectors contain an X-radiation shield - use only the manufacturer's specified anode connectors. High voltage must be measured each time servicing that involves power supply, horizontal deflection or high voltage circuits is performed. Correct operation of the Xradiation circuits must also be confirmed each time these circuits are serviced (X-radiation circuits may also be called "horizontal disable" or "hold-down" circuits). Read and apply high voltage limits and, if the chassis is so equipped, the X-radiation protection circuit specifications. These limits and specifications are given on instrument labels and are included in this service data. High voltage is maintained within specified limits by closetolerance safety-related components (and adjustments) in the high voltage circuit. If high voltage exceeds specified limits, check each safety related component specified on the schematic and take corrective action.

ANTENNA LEAKAGE RESISTANCE CHECK - With the instrument AC plug removed from the AC source, connect an electrical jumper across the two AC plug prongs. Place the instrument AC switch (if applicable) in the "on" position. Connect one lead of an ohmmeter to the AC plug prongs and touch the other ohmmeter lead, in turn, to each (exposed) antenna input terminal screw and/or coaxial connector. If the measured resistance is less than 1.0 Megohm, or greater than 5.2 Megohm, an abnormality exists which must be corrected before the instrument is returned to the customer. Repeat this test with the AC switch in the "off" position.

reading

should be

< 0.5mA

earth

ground

2-wire

cord

DEVICE UNDER

TEST

also test with

plug reversed

(use ac adapter

plug as required)

probe all exposed

metal

surfaces

LEAKAGE

CURRENT

TESTER

LEAKAGE CURRENT HOT CHECK FOR 2-WIRE OR 3-WIRE GROUNDED CORD SETS - With the instrument completely reassembled,

plug the AC line cord into the mains AC outlet at normal line voltage via a non-polarized adapter. DO NOT GROUND THE 3RD PRONG OF THE ADAPTER AND DO NOT USE AN ISOLATION TRANSFORMER. Use a leakage current tester or metering system that complies with American National Standards Institute (ANSI) C101.1 Leakage Current for Appliances and with Underwriters Laboratories (UL) 1492 (Section 67). With the instrument AC switch first in the "on" position and then in the "off" position, measure from a known earth ground (metal water pipe, conduit, etc.) to all exposed metal parts of the instrument (antennas, handle bracket, metal cabinet, screwheads, metallic overlays, control shafts, etc.). Any current measured must not exceed 0.5 milliampere. Reverse the adapter plug in the outlet and repeat the test. ANY MEASUREMENTS NOT WITHIN

THE LIMITS SPECIFIED HEREIN INDICATE A POTENTIAL SHOCK HAZARD THAT MUST BE ELIMINATED BEFORE RETURNING THE INSTRUMENT TO THE CUSTOMER OR BEFORE CONNECTING THE ANTENNA OR ACCESSORIES. If a

leakage current tester is not available, connect a 1.5 Kohm, 10 Watt resistor, in parallel with a 0.15 µF, 150V capacitor, between earth ground and each exposed metal part of the instrument (as shown above). Use an AC voltmeter with at least 5000 ohm/volt sensitivity to measure the potential across the resistor. The potential measured for any exposed metal surface must not exceed 0.75 volts.

Page 1-2

DTV307

MODEL-TO-MAJOR ASSEMBL Y CROSS REFERENCE

KEY TO MAJOR ASSEMBLIES

I1 - I/O PCB (1552392A)

B1 - Frame Comb PCB (1552390A)

M1- Deflection/Power Supply PCB (1553100B)

C1 - Red CRT driver PCB (1558634B)

O1 - Front A/V PCB (1552388A)

C2 - Green CRT driver PCB (1558635B)

P1 - Adapter PCB (1558640C)

C3 - Blue CRT driver PCB (1558636B)

R1 - IR Receiver PCB (1550627A) D1 - DM1 Assembly D2 - DM1-CR Assembly

S1 - Deflection SIP PCB (1552391A)

F1 - Front Panel Assembly PCB (1550420C)

H1 - Convergence Amp PCB (1558574A)

T1 - 2nd Tuner/IF PCB(1507271O)

V1 - Digital Convergence Module PCB (1558637B)

CROSS REFERENCE

HD65W20JX1 ..................................... B1,C1,C2,C3,D2,F1,H1,I1,M1,O1,P1,R1,S1,T1,V1

HD65W20YX1 .................................... B1,C1,C2,C3,D2,F1,H1,I1,M1,O1,P1,R1,S1,T1,V1

P61310JX1 .......................................... B1,C1,C2,C3,D2,F1,H1,I1,M1,O1,P1,R1,S1,T1,V1

P61310JX2 .......................................... B1,C1,C2,C3,D1,F1,H1,I1,M1,O1,P1,R1,S1,T1,V1

P61310JX3 .......................................... B1,C1,C2,C3,D1,F1,H1,I1,M1,O1,P1,R1,S1,T1,V1

P61310JX4 .......................................... B1,C1,C2,C3,D2,F1,H1,I1,M1,O1,P1,R1,S1,T1,V1

PS65000JX2 .................................... B1,C1,C2,C3,D1,F1,H1,I1,M1,O1,P1,R1,S1,T1,V1

SPECIFICATIONS

General Specifications

Power Requirements: 95-132VAC, 50-60Hz Power Consumption: 250 watts maximum

RF Specifications

Tuning System: Quartz-controlled multiband

frequency synthesis

Band Coverage: VHF channels 2-13

UHF channels 14-69

Cable channels 1-125 Frequency Coverage: 54-806 MHz Antenna Inputs: 75-ohm UHF/VHF Sensitivity: 10uV

DBS IF Tuning Range

IF Tuning Range 950 - 1450 Mhz

Audio Specifications

Frequency Response: 50-20,000 Hz (@ rated output) Stereo Modes: Dbx stereo, Enhanced SRS Au x Audio In: 250mVRMS typical,

A/V Input: 500mVRMS typical Input Impedance: 50Kohms (source impedance

Power Output: 10 watts/channel Fixed Audio Output: 250mVRMS into 10Kohms

Headphones: 16 ohms recommended

Remote Control

Transmission System: Digitally encoded infrared light Battery Life: One year normal use

2.25VRMS maximum

should be < 2Kohms) RMS into 8 ohms <0.5% THD

Video Specifications

Aux Video In: 1Vp-p, 75 ohms, neg sync SVHS Luma In: 1Vp-p, 75 ohms, neg sync SVHS Chroma In: 286mVp-p burst, 75 ohms Aux Video Out: 1Vp-p, 75 ohms, negative sync A/V Input: 1Vp-p, 75 ohms, neg sync Other Inputs: Component Video (Y, PR, PB)

Specifications subject to change without notice.

Page 1-3

DTV307

SCHEMATIC NOTES

1 . Resistor values are in ohms (K = X1,000; Meg = X1,000,000). Tolerance is 5%, unless otherwise specified. [ ] Indicates a flat (type 1206) surface-mounted device; 1/8 watt unless otherwise specified. / \ Indicates a flat (type 0805) surface-mounted device; 1/10 watt unless otherwise specified.

(no markings) indicates 1/4 watt, 5% tolerance axial-leaded device, unless otherwise specified.

2 . Capacitor values 1.0 and above are in picofarads; values less than 1.0 are in F, unless otherwise specified.

• • Indicates a cylindrical surface mounted device; 50 volt unless otherwise specified.

[ ] Indicates a flat (type 1206) surface-mounted device; 50 volt unless otherwise specified. / \ Indicates a flat (type 0805) surface-mounted device; 50 volt unless otherwise specified.

(no markings) indicates a radial- or axial-leaded device; 50 volt unless otherwise specified.

3 . DC voltages measured with NTSC color bar signal applied (via RF channel 3), except for audio voltages, which are measured

with MTS stereo 1KHz signal applied. Voltages in parentheses ( ) indicate standby mode.

4 . Waveforms measured with NTSC color bar signal applied (via RF channel 3), except for audio waveforms, which are measured

with MTS stereo 1KHz signal applied.

5 . Special symbols:

Indicates schematic zone locator Indicates service test point Indicates wire-wrap stake Indicates connection via point-to-point wire Indicates jumper wire (top side) Indicates zero ohm chip (bottom side) Indicates "hot" ground Indicates "cold" ground

SERIAL NUMBER LOCA TION

Serial Number/Model Number Location on Chassis

Page 1-4

DTV307

Circuit Protection

Fusible Device Circuit Protected Physical Location

F14200 (6.0 A, 125V) AC Input Power Supply PCB, Left rear chassis F14100 (3.0 A, 125V) AC Input DM1 Power Supply PCB, Left rear

COMPONENT NUMBERING SYSTEM

Serviceability of this chassis is enhanced by prominent road mapping on the top and bottom of the circuit boards. The component numbering system relates to general circuit areas as follows:

11300 Series - Audio Outputs 11400 Series - Audio Input Switching 11500 Series - Audio Compression 11700 Series - SRS Audio 11800 Series - Audio TVB 11900 Series - Audio Power Amp, AVR 13100 Series - System Control (Control) 13200 Series - I/O Control 13400 Series - User Controls (Front Panel Assembly) 14100 Series - Power Supply (Regulator) 14200 Series - Power Supply (AC Input) 14300 Series - Deflection SIP 14400 Series - S-Cap Switch 14500 Series - Vertical 14600 Series - Standby Power Supply 14700 Series - Horizontal, HV 14800 Series - Scan 16300 Series - Frame Comb 16500 Series - Video Switching 17100 Series - 2nd 17300 Series - 2nd Tuner

Tuner

17400 Series - 2nd Tuner, PLL 18100 Series - F2PIP 18500 Series - Video I/O 19100 Series - Adapter 19300 Series - Convergence Amps 19500 Series - Digital Convergence 19700 Series - Convergence Power Supply 22300 Series - Video Control 22400 Series - Digital Interface 24500 Series - LNB Power Supply 24800 Series - Deflection SIP 25100 Series - Red CRT Drive 25300 Series - Green CRT Drive 25500 Series - Blue CRT Drive 26100 Series - FAV 27900 Series - 2nd Tuner IF 32100 Series - 2nd Tuner IF Out 38300 Series - Sync Processing 41100 Series - Fan Shutdown

Page 1-5

DISASSEMBLY PROCEDURES

Back Panel Removal

The cabinet back panel is held in place with several 1/4" hex head screws. The number of (and placement of) screws varies with the cabinet design. Remove screws as necessary to release the cabinet back panel.

Mirror Removal

1. Remove the screen assembly.

2. Remove four screws located on the back of the instrument holding the screen assembly.

Chassis Assembly Removal

1. Remove the back cover.

2. Remove two 1/4" hex screws holding the chassis to the bottom of the cabinet.

3. Disconnect cables as necessary to service. Most of the cables can be left connected for servicing by releasing the wire ties and holders. Remove the DM1 Power Supply for better access.

Note: Lead dress is critical on this chassis. Make sure all

cables, wires etc, are returned to their original lead dress. See lead dress photos at the end of this section.

I/O Board Panel Removal

1. Remove the back panel.

2. Remove four screws holding the upper half of the I/O board panel and remove.

3. Remove the remaining hex screws and four torx screws.

4. Release one tab on each side of the panel and remove.

DM1 Module Removal

1. Remove the back panel.

2. Release tabs on each side of the DM1 Power Supply and remove.

3. Remove two screws holding main chassis assembly.

4. Remove two screws holding DM1 to chassis.

5. Lift up and slide out of chassis.

6. Remove three screws holding DM1 mounting bracket to chassis assembly.

7. Disconnect cables and remove DM1 from chassis.

Speaker Grill Assembly Removal

Pull the speaker grill assembly away from the front of the instrument.

Screen Assembly Removal

1. Remove the speaker grill.

2. Disconnect the in-line connector coming from the Auto Convergence sensors.

3. Remove the hex screws located along the bottom of the screen assembly and back of the instrument.

4. Pull out slightly on the bottom of the screen assembly and lift the assembly up to remove.

5. Remove two hex screws holding FPA assembly to screen frame.

6. Unplug cable to Front A/V assembly.

CRT Removal Note: Be sure to mark the location and orientation of the

tube assemblies as they are removed. When reassembling, position the assemblies back to their original position.

1. Remove the screen assembly.

2. Remove the 1/4" hex head screws securing the top CRT access panel (located on top of the CRT's) and remove the panel.

3. Remove the 1/4" hex head screws securing the front CRT access panel (located on the front bottom of the cabinet) and remove panel.

4. Loosen the screw near the bottom of the CRT neck securing the CRT driver circuit board.

LOOSEN SCREW

Fig. 2-1 Loosen screw to remove CRT driver circuit board

5. Pull the CRT driver circuit board off the end of the tube.

6. Carefully mark the location of the SVM coil and remove. When reinstalling the SVM coil, the pad with the white lead soldered to it should be placed on the top of the tube(over the spacing bead) between the 2nd and 3rd grids (Fig 2-2 on page 2-2).

WHITE LEAD PAD

Page 2-1

DISASSEMBLY PROCEDURES (Continued)

WHITE LEAD PAD

YOKE CLAMP SCREW

Fig. 2-2 SVM coil placement

7. Loosen the screw on the yoke clamp and remove the yoke(Fig 2-3).

MOUNTING BOLTS

Fig. 2-4 Mounting bolts location

10. Remove the grounding strap and spring.

11. Pull the CRT straight up out of the frame to remove.

YOKE CLAMP SCREW

Fig. 2-3 Yoke clamp

8. Release the anode lead from the HV splitter by pulling the lead straight out (do not twist). Do not remove the anode lead from the CRT.

9. Remove the four mounting bolts(Fig. 2-4).

Yoke Replacement

1. Perform steps 1 thru 7 under "CRT Removal".

2. Remove the hot melt glue from the four tabs on the plastic housing.

3. Release the four tabs and remove the housing.

4. Unsolder the yoke and convergence leads taking note of the color and orientation of the leads.

Second Tuner Circuit Board Removal

1. Twist the tabs to remove the Second Tuner circuit board.

Side Fan Removal

1. Disconnect P41125.

2. Twist one tab on each side of the fan assembly.

3. Pull the top of the fan out first, then the rest of the assembly to remove.

Page 2-2

DISASSEMBLY PROCEDURES (Continued)

Critical Lead Dress

Page 2-3

DISASSEMBLY PROCEDURES (Continued)

Critical Lead Dress

Page 2-4

DTV307 CHIP COMPONENT REMOVAL

Replacement Procedure for Chip Removal

The following procedures are recommended for the replacement of the chip components used in this unit. Failure to follow these procedures may lead to damage to the copper traces and pads on the printed circuit boards.

1.Preparation for replacement

a. Soldering Iron: Use a pencil-type soldering iron

using less than 30 watts.

b. Solder Type: Eutectic Solder, Tin 63%/Lead

37%, is recommended.

c. Soldering Time: Do not apply heat for more than

4 seconds.

d. Preheating: Chip capacitors must be preheated

before installation. (130 degrees - 150 degrees C).

Note: Chip component must not be reused after removal.

Excessive mechanical stress and rubbing of the component electrode must be avoided.

2. Removing the chip component (Fig. 2-3): Grasp the chip component body with tweezers and

alternately apply heat to both electrodes.

Note: Do not attempt to lift the component off the board

until the component is completely disconnected from the board by a twisting action. Attempting to

remove the component before it has completely been disconnected can break the copper foil on the printed circuit board.

3. Installing a chip component

a. Presolder the contact points on the circuit board

(Fig. 2-4).

Fig.2-4, Chip Component Presolder

b. Hold the component in position with tweezers and solder the electrodes as shown (Fig.2-3).

Figure 2-3, Removing Chip Components

When the solder on both electrodes has melted, remove the chip component with a twisting motion.

Fig. 2-3 - Chip Component Installation

Note: Do not glue the replacement chip component to the

circuit board.

Page 2-5

DTV307

ALIGNMENT PROCEDURES

Operating Conditions

Unless otherwise noted, the following conditions must be

observed when aligning the DTV307 chassis:

1. Chassis must be operated from a 120VAC isolation transformer, with line voltage set to 120VAC (±2.0V).

2. Picture controls (black level, contrast, etc.) must be set to factory presets via the Picture Quality menu.

3. Procedures must be performed in the sequence given.

4. A 10X probe must be used for oscilloscope and frequency measurements.

5. Minimum warm-up time is 10 minutes.

Required Test Equipment

- Dual-Trace Oscilloscope

- Digital Voltmeter

- Frequency Counter

- Audio Signal Generator

- NTSC Signal Generator (B&K 1249, or equivalent)

- MTS Signal Generator (B&K 2009, or equivalent)

- Sweep/Marker Generator (or Standard Signal Generator)

- TAG001 Service Generator (stock # 215568)

- YPrPb Signal Generator (DVD player with YPrPb)

- DC Power Supply (5.0V/0.25A) for TAG001

- Chipper Check® software

- Chipper Check® interface box and computer

All alignments with the exception of basic color temp

require the use of Chipper Check® software and interface box.

X-Ray Shutdown Check

The following procedure should be performed prior to, and

upon completion of service:

1. Set Black Level and Contrast to maximum. Momentarily apply a short between the shutdown test points (JW14901- located at back edge of chassis) and ground. The instrument must shutdown immediately, then turn back on after ~ 2 seconds.

2. Apply and maintain a short between the shutdown test points. The instrument must shutdown immediately and remain shutdown (the instrument will attempt to restart three times, then remain off).

3. Remove the short from JW14901.

4. Enter the Service Mode and reset the error code parameter(s) to "0".

Entering the TV Service Mode Using the Front Panel Controls

1. Press and release the POWER button to turn the instrument on.

2. Simultaneously press and hold the TV/DIRECTV

and the Channel Down Buttons on the front of the TV.

The instrument will display the following menu: The CH ∧ and CH ∨ buttons on the front panel (or the

P: 0 V: 0

remote transmitter) are used to change the parameter (P) number. The VOL + and VOL - buttons are used to change the value (V).

NOTE: Attempting to change the parameter number (using

CH ∧ or CH ∨) at this point will cause the instrument to exit the service mode. A valid security code must be entered (using VOL + or VOL -) before selecting an alignment parameter.

Security Codes

When the service mode is first turned on, the parameter will be "0", which does not correspond to an alignment. This is the security code parameter, the purpose of which is to prevent accidental entry into the parameter groups. The value (V) must be set to 76 for Front panel access to Chassis Alignments. The value (V) must be set to 80 for Digital Convergence mode. The value (V) must be set to 90 for the Warranty Clock. The value (V) must be set 200 for Chipper Check®. Once Chipper Check® mode (V=200) is selected, the Chipper Check® interface box will take control of the instrument and the front panel will become inoperative.

Once a security code has been set, pressing CH ∧ or CH will result in the following display:

Service Mode

Many of the alignments for this chassis are software-driven; adjustments are made by modifying parameter values using Chipper Check and the service menu. When parameter values are modified, the corresponding T-chip registers, tuner registers and EEprom locations are updated.

A list of the software alignment parameters accessable using the front panel is shown in Table 2. The remainder of the alignments require Chipper Check®. Even though some of the geometry alignments are available through the front panel service menu, adjustment is not recommended. Alignment in one mode will interact and affect the displays of the other modes.

Page 3-1

P: YY V: ZZZ

Where: YY = parameter number

ZZZ = current value

At this point, the CH ∧ and CH ∨ buttons can be used to

change the parameter number and the VOL + and VOL buttons can be used to change the value of the parameter selected.

DTV307

ALIGNMENT PROCEDURES (Continued)

Error Codes

If certain failures occur in the chassis, error codes will be stored in the chassis EEprom. These error codes are displayed in parameters "1", "2" and "3". Parameter "1" stores the error code for the first failure experienced by the instrument. Similarly, parameter "2" stores the error code for the second failure. Parameter "3" is automatically updated to display the error code for the most recent failure experienced by the instrument. Error codes are summarized in Table 1.

The presence of a "0" in the error code values indicates that no failures have occurred since the time when the error code parameters were reset. These error codes can (and should) be reset to "0" after servicing with the VOL + and VOL - buttons.

Because a failure of a bus IC is a possible reason for needing service, normal acknowledgment checking is disabled in the service mode. If an IIC device has failed, its address will be stored in the error code area.

Exiting The Service Mode

The service mode can be exited at any time by pressing the INFO button on the remote (except when in ChipperCheck mode). No additional steps are required to write new data into the EEprom(s); new data is entered as parameter values are changed.

CHASSIS ALIGNMENT

The DTV307 chassis requires the use of ChipperCheck®, a TV/PC interface box, and a suitable computer (min. 486DX/ 33MHz PC with 8Meg memory recommended) for the majority of the alignments. Basic geometry and color temperature are the only alignments accessable through the front panel. These adjustments have been included in this service manual as front panel procedures but can also be performed using ChipperCheck®.

ChipperCheck® software and the TV/PC interface box are available from:

AKB Mode (Parameter 27)

Do not change front panel adjustment parameter 27, AKB mode. These are used for factory alignments only. 00 is the default setting. All other adjustment values may set at nominal or half of their full range values when there is a question of what value is needed to begin alignments.

High Voltage Adjustment

The high voltage in this instrument is very critical and requires special test equipment to measure and adjust. Field alignment is not recommended. If one of the following components is replaced the remainder of the components listed must be replaced at the same time. These components are packaged together in a kit (see parts list for stock number): R14767, R14778, R14780, R14776 and R14777. Adjustment of high voltage will not be necessary.

Note: To remove the high voltage leads from R14767, twist

the lead (at least 360deg) while pulling up.

XRP Adjustment

The XRP circuit in this instrument requires special test equipment to measure and adjust. Field alignment is not recommended. If one of the following components is replaced the remainder of the components listed must be replaced at the same time. These components are packaged together in a kit (see parts list for stock number): CR14900, R14900, R14901, R14902, R14904, R14906 and Q14901. Adjustment of XRP will not be necessary.

Vertical Movie Mode (Parameter 14)

1. Always set to "0".

Vertical Slope/Vertical Start Scan (Parameters 15, 16, 17)

These parameters are preset at the factory and should not be aligned.

TCE Publications 10003 Bunsen Way Louisville, KY 40299 Tel. 502-491-8110

Instructions for the operation of ChipperCheck® software and connection of the TV/PC interface are included as context-sensitive help files in the ChipperCheck® software.

Focus Adjustment

1. Tune the instrument to receive a crosshatch signal.

2. Preset Contrast to maximum.

3. Set the value of parameter 41(RGB output mode) to 02.

4. Adjust the Green Mechanical Focus control, located on the CRT assembly for best overall focus.

5. Adjust the Green Electrical Focus control, located behind the speaker grill for best overall focus.

6. Repeat procedure for the red (value 01) and blue(value

03) CRT's.

Page 3-2

Scan ZVS

1 . Apply an NTSC flat white field to AUX 1.

2. Connect a DVM to the +76VRUN power supply (C14111+).

3. Adjust R14101 for 76 + 0.1VDC.

DTV307

ALIGNMENT PROCEDURES (Continued)

rorrE

edoC

1seYliaFrewoPlaitinI--

3seYnuRV21+--

6ebyaMhctiwSoediV-S1NUR00561UeruliaFylppuSroCI 7seYssoLnacS--noitcelfeDnacSfossoL 9seYCIoediV1NUR00322UeruliaFylppuSroCI

01ebyaMROPPIP2F1NUR00181UeruliaFylppuSroCI 11ebyaMredoceDoeretS2NUR10713UeruliaFylppuSroCI 21ebyaMdehctaLRVA--evitcARVA

31seYdeppotSnaF--10131U

61seY 81seYsuBybdnatSCII--10131UeruliafatadrokcolcCII 02seY

22reveN

42reveN

52reveN

62syawlA

54/44ebyaMCIPIP2F1NUR00181UeruliaFylppuSroCI

56/46ebyaMCADFIPIP2NUR20972UeruliaFylppuSroCI 76/66ebyaMCADrenuTniaM1NUR20623UeruliaFylppuSroCI

86ebyaMCADnoitcelfeD2NUR00842UeruliaFCI

37/27ebyaMcorPCNYS2NUR00383UeruliaFylppuSroCI

921/821ebyaMredoceDoeretS1NUR10713UrorrEylppuSroCI 431ebyaM 631ebyaMredoceDCSTN1NUR00322UeruliaFylppuSroCI

631ebyaMBVT2NUR00811UeruliaFylppuSroCI 041ebyaM

161/061ebyaMMORPEEO/IYBDTS20131UeruliaFylppuSroCI

761/461ebyaM

961/861ebyaM

781/681ebyaMCIDSO1NUR20231UeruliaFylppuSroCI 291ebyaMLLPrenuTPIP2NUR10471UeruliaFylppuSroCI 491ebyaMCADFIPIP2NUR20972UeruliaFylppuSroCI 691ebyaMLLPrenuTniaM1NUR10552UeruliaFylppuSroCI 891ebyaMCADFIniaM1NUR20623UeruliaFylppuSroCI

022ebyaMorciMmetsyS--10131U

rewoP

lataF

rorrE suB eciveD noitidnoC

nuRV21+

tuoporD

nuRV21+

rotinoM

ro1nuRCII

rorrEsuB2nuR

kcatSerawtfoS

wolfrevO

er'uoY-sekirtS-4

derruccOtuO

ecnegrevnoC

rorrEytiraP

ecnegrevnoC

detlaHpooL

ecnegrevnoC

evitcanItuptuO

VAetisopmoC

hctiwS

noitcelfeD

rossecorP

renuTniaM

MORPEE

noitcelfeD

MORPEE

renuTdn2

MORPEE

--10131UeruliafatadrokcolcCII

--10131U

--10131UorciMybdetceteDtluaF

--20591U

1NUR10561UeruliaFylppuSroCI

2NUR05341UeruliaFylppuSroCI

1NUR10623UeruliaFylppuSroCI

2NUR45341UeruliaFylppuSroCI

2NUR30972UeruliaFylppuSroCI

nuRV21+kcehC

noitalugeRnuRV21+kcehC

tiucriCtceteDnaFronaF

eruliaF

teseR.snoitidnoCsuoiraV

.metsys

edoMtnerruCrofMORPEE

detpurroCsi

tonpooLecnegrevnoC

ylreporPgnitarepO

situptuOecnegrevnoC

evitcanI

snoitacinummuoCoN

10131UneewteB

20591Udna

Table 1 - Service Menu Error Codes

Page 3-3

DTV307

ALIGNMENT PROCEDURES (Continued)

Parameter # Para m eter Na m e Value Range

00 Service M ode E ntry 76 S et V:76, then in cr em e n t P :

01 Err or Dete ct io n ( 1s t)

02 Error Detection (2nd)

03 Error D e tec tion (la st)

04 Ho rizo ntal P hase 00 .. 63

05 Width Align 00 .. 63

06 Width 00 .. 63

07 E/W P arabola 00 .. 63

08 E/W Trap 00 .. 07

09 E/W Corne r 00 .. 6 3

10 Vertical O ffset 00 .. 07

11 Vertical Amp A lign 00 .. 63

12 V e rtical A m p D elta 00 .. 15

13 Ve rtical C enter 00 .. 63

Notes/Comments/Nominal

Values

Note: Changes VerticalAmpDelta

EEPROM, and Updates VerticalAmp

14 V ertical Movie Mode 00 .. 02 0=N ormal; 1=M ovie1; 2=Movie2

15 Vertical Slope MSB 00 .. 255

16 Vertical Slope LSB 00 .. 255

17 V er t ical S ta r t S c a n 00 .. 59

18 Red Cutoff 00 .. 255

19 Green Cutoff 00 .. 255

20 Blue C utoff 00 .. 255

21 Video Mode Cutoff 00 .. 255

23 Blue Drive 00 .. 127

24 Video Mode Light Output 00 .. 117

25 Text Mode Cutoff 00 .. 255

26 Text Mode Light Output 00 .. 107

27 AKB M ode 00 .. 01

Red Drive

00 ..127

00 = Off; 01 = On

28 Red Cutoff Overide 00 .. 255

29 Green Cutoff Overide 00 .. 255

30 Blue Cutoff O veride 00 .. 255

31 Cutoff (Overide) 00 .. 255

Table 2 - Service Menu Chart

Page 3-4

DTV307

ALIGNMENT PROCEDURES (Continued)

32 Comb D/A (Composite) 00 .. 127

33 FPIP Cont rast (Composite) 00 .. 127

34 FPIP Fine T int (Com posite) 00 .. 07

35 FPIP Saturation (Composite) 00 .. 127

36 Comb D/A (S-Video) 00 .. 127

37 FP IP Contrast (S-Video) 00 .. 127

38 FPIP Fine Tint (S-Video) 00 .. 255

39 FPIP Saturation (S-Video) 00 .. 127

40 Digicon Bus Control 00 .. 01

4 1 R GB Out put Mo de 0 0 . . 0 3

0 0 = e n able co mmunica tio n bet ween

Convergence Micro and Digital

Co n v e r gen c e Micro;

01 = Disable communicatio ns

0 = N o r mal

01 = Re d

02 = Green

03 = Blue

00 Digital Convergence Mode 80

00 P TV Sensor P ositioning 82

00 Warranty Clock Menu 90 Security Pass Number for W arranty M enu

PTV Restore Digital Convergence Factory

Alignment Data

PTV Save Digital Convergence Factory

Alignment Data

Securit y P ass Num ber fo r Convergence

Mode

Securit y P ass Num ber for

Sensor Positioning

Sec urit y P ass Num ber f or

Restore Factory Align Data

Securit y P ass Number for Save

Alignment Data

Table 2 (continued) - Service Menu Chart

Page 3-5

DTV307

ALIGNMENT PROCEDURES (Continued)

DM1 Service Menu

A seperate Service Menu is included in the DM1 module. The purpose of this service menu is to assist the technician in diagnosing problems with the DM1 module.

Entering the DM1 Service Menu

1. Press and Release the POWER button to turn the instrument on.

2. Simultaneously press the MENU/OK and CHANNEL DOWN on the Front Panel Assembly to enter the service menu.

The instrument will display the following menu.

CAM ID - Also comes from the verifier software. Should be same number as written o the CAM.

DEMOD SIGNAL - If system is tuned to a BBS or HD-SAT signal, will give the signal strength between 0 and 100.

CHECKSUM - 3 checksums will be displayed. I: internal ARM ROM checksum H: checksum on the 2 highest megabytes of flash L: checksum on the 2 lowest megabytes of flash

EEPROM - The AVDEC and Tuner EEPROM are checked. SYSTEM RAM - The transport, external and cache RAM are

tested.

VIDEO DRAM - The video DRAM is tested. MODEM - Will call the phone number entered in the Modem

Number Menu. A complete set of modem test are performed. PHONELINE LEVEL - Will display the voltage measured on

the phone line. DIAL TONE - Checks dail tone. Will display whether the

dialing method is DTMF or Pulse.

Press the Menu/OK on FPA or OK button on Remote to begin Service Test. The Service Test screen will test the system and place the results in the right-hand side of the screen.

AV&TL - AV (Audio/Video) and TL (Tuner Link) are identifiers stored in the EEPROMS.

ROM - The first 4 charaters are the "software model number". The next set of charaters will be the software version. If there is a valid patch, then its ID is displayed as the next 4 charaters. "M" is displayed if Macrovision is enabled. "C" is displayed if Colorburst is enabled.

Example: 028a A04.26 B03.07 MC00

software software patch ID macrovision model number version colorburst enable

CB HISTORY - Indicating the diagnostics for the last 5

attempted calls. The "Information" screen will display AV&TL, ROM,

VERIFIER/CAM and CAM ID test results. Press the Menu/ OK on FPA or OK button on remote to run these tests. The "Odomter" screen will display the Activation Date a DIRECTV signal is acquired for the first time. The Service Counter indicates the number of hours the system has been under power (not just turned on). The "Phone Prefix" screen allows you to enter a 1-digit to access an outside line and also a Call Waiting disable code as well. The "Moden Number" screen will allow a 11-digit phone number to be used during the System Test.

VERIFIER/CAM - Number comes from the verifier software. The first number is the software version. The next number is the CAM version.

Page 3-6

DTV307

ALIGNMENT PROCEDURES (Continued)

DTV307 Color Temperature Alignment

Color temperature alignment for the DTV307 projection instrument becomes complex. AKB is not utilized in this instrument and color temperature must be setup for both user selectable color temperature modes, "Normal" and "Warm".

Color temperature is actually setup for only one user mode, then the remainder of the settings are calculated and placed into the proper EEPROM locations. Proper color temperature setup is dependant upon screen control setup. This adjustment is done only once and used as a "reference" for the remaining adjustments.

The order of adjustment is important. The proper order is:

1. Screen Control Setup

2. 2.14H "Video" Mode, "Normal" Temperature.

3. 2.14H, "Video" Mode, "Warm" Temperature.

Screen Control Setup

If screen control setup is done properly, the original color temperature settings will probably be acceptable.

NOTE: AKB will remain "OFF" (0) for all operating

conditions of the DTV307 including all alignment procedures. AKB is not used in the DTV307 instrument at this time.

PRESETS:

To begin, set the instrument to receive a "Comp" input on the Component Video Input (Y, PR, PB) on the rear jack panel using a clean average video signal. Preheat the instrument for at least 20 minutes with an active video display.

In the consumer menu, under Picture Quality, set the

Picture Presets to "Normal Lighting". Then using the Picture Controls, set Contrast to "maximum" and Color to

"minimum". Set Color Warmth to "Normal".

5. Set Video Mode Light Output (P24) to "V:64".

6. Set Blue Drive (P23) to V:64.

7. Set Red Drive (P22) to V:64.

8. Set Video Mode Cutoff (P21) to V:64.

9. Set Blue Cutoff (P:20) to V:127.

10. Set Green Cutoff (P:19) to V:127.

11. Set Red Cutoff (P:18) to V:127.

12. Making certain the 0 IRE Flat Field pattern (TP2) is still displayed, observe the LED's located on the kine boards on the neck of the CRT's. Adjust the Video Mode Cutoff (P21) until any LED illuminates. Continue increasing P:21 until the second of the three LED's illuminates. It does not matter at this point if the first LED goes dim.

13. Now adjust the Red, Blue or Green cutoff control for the LED THAT HAS NOT YET ILLUMINATED until that LED also lights.

NOTE: If the cutoff control runs out of range, increase the

Video Mode Cutoff (P:21) until the final LED lights.

14. Now decrease the two remaining cutoff controls until the respective LED's are just lit.

15. Continue fine adjustment of the Red, Green and Blue cutoff controls until all three LED's are full on.

16. If a colorimeter is available adjust the screen controls for x=.300, y=.310 and Y=1.0 +0.25. If not, increase the screen controls to provide a low level gray pattern. A 10 Bar Gray Scale or similar pattern may be used to provide a known gray pattern. The important point is when the adjustment is complete a very low level uniform gray pattern should be visible when the flat field gray pattern (TP2) is placed on the screen.

DO NOT ADJUST THE SCREEN CONTROLS AGAIN AFTER THIS STEP!!!

In the consumer menu under Screen, set the Menu

Background Color to "Transparent".

Four test patterns, will be required for the procedure. TP1 is a 12 IRE 50% display window for setting the screen controls, lowlights. TP2 is a 0 IRE flat field for setting cathode cutoffs. TP3 is a 100 IRE flat field for setting highlights. TP4 is a 100 IRE 50% Window for setting light output.

To Adjust the Screen Control:

1. Apply TP1 to the Component Video Input (Y, PR, PB).

2. Make certain the preheat and preset conditions have been met.

3. Enter the serviceman menu using the front panel buttons by pressing simultaneously "TV/DIRECTV" and "CHANNEL DOWN" . Use "VOL UP" to place the "V:" value to "76". When a parameter is specified use "CH UP" or "CH DN" to change to the correct parameter number, then use "VOL UP" or "VOL DN" to change the value of the paramter.

4. Set all three screen controls on the focus/screen assembly to minimum (full CCW).

17. Exit the serviceman menu by pressing "INFO" on the remote control. This stores the new values to the EEPROM and completes screen control setup.

If a colorimeter is not available color temperature setup and screen control adjustment should end here. If a colorimeter is available continue to the next section.

To Adjust 2.14H "Video" Mode "Normal" Color Temperature:

1. Apply TP1 to the Component Video Input (Y, PR, PB) and adjust the instrument for normal reception.

2. Make certain the preheat and preset conditions have

been met. In the consumer menu, under Picture Quality, set the Picture Presets to "Normal Lighting". Then using the Picture Controls, set Contrast to "maximum" and Color to "minimum". Set Color Warmth to "Normal".

Page 3-7

DTV307

atte

ALIGNMENT PROCEDURES (Continued)

50% 12 IRE

w P

Win

50% 100 IRE

w P

Win

Window Patterns for Color Temperature Setup

Page 3-8

DTV307

ALIGNMENT PROCEDURES (Continued)

3 . Enter the serviceman menu using the front panel buttons

by pressing simultaneously the "TV/DIRECTV" and "CHANNEL DOWN". Use "VOL UP" to place the "V:" value to "76". When a parameter is specified use "CH UP" or "CH DN" to change to the correct parameter number, then use "VOL UP" or "VOL DN" to change the value of the parameter.

4. Set the RGB Output Mode (P:41) to V:2. This changes the screen output to green only.

5. Using the colorimeter, adjust Video Mode Cutoff (P:21) for Y=0.420.

6. Change the video test pattern to TP3 (100 IRE Flat Field). Measure the light output with the colorimeter and record as LO#1_____ .

7. Change the video test pattern to TP4 (100 IRE Window). Measure the light output with the colorimeter and adjust the Video Mode Light Output (P:24) to obtain a reading

1.78 times that of LO#1. Record it as LO#2______ .

8. Change the video pattern back to TP1 and repeat step 57 if necessary.

9. To return all three colors, set RGB Output Mode (P:41) to V:0.

10. Change the video test pattern to TP1 (12 IRE Window) and adjust the Red, Green and Blue Cutoffs (P:18, P:19 and P:20) and Video Mode Cutoff (P:21) using the colorimeter for x=0.300, y=0.310, Y=0.600.

11 . Change the video test pattern to TP3 (100 IRE Flat Field).

Set highlight temperature using the Red and Blue Drives (P:22 and P:23) for x=0.300, y=0.310.

12. Repeat steps 10 and 11 as needed for accuracy.

13 . Record the values for P:18, P:19, P:20, P:21, P22, P23 and

P24. These values will be transfered to the same parameters in the "Warm Color Temp Mode" to be used as a starting point.

14. Exit the serviceman menu by pressing "INFO" on the remote control.

15. Enter the customer menu, select "Color Warmth". Change from "Normal" to "Warm" then back to "Normal" to set the correct cutoff values.

To Adjust 2.14H "Video" Mode "Warm" Temperature

Light Output:

1. Set the instrument to receive a "Comp" input on the Component Video Input (Y, PR, PB) on the rear jack panel using a clean average video signal. Preheat the instrument for at least 20 minutes with an active video display.

2. In the consumer menu, under Picture Quality, set

Contrast to "maximum", "Color" to "minimum", Color Warmth to "Warm".

3. In the consumer menu under Screen, set the Menu Background Color to "Transparent".

4 . Enter the serviceman menu using the front panel buttons

by pressing simultaneously the "TV/DIRECTV" and "CHANNEL DOWN". Use "VOL UP" to place the "V:" value to "76". When a parameter is specified use "CH UP" or "CH DN" to change to the correct parameter

number, then use "VOL UP" or "VOL DN" to change the value of the parameter.

5. Set P18, P19, P20, P21, P22, P23 and P23 to the value recorded in the previous 2.14H "Normal" setup to be used as a starting point.

6. Change the video test pattern to TP1 (12 IRE Window) and adjust the Red, Green and Blue Cutoffs (P:18, P:19 and P:20) and Video Mode Cutoff (P:21) using the colorimeter for x=0.313, y=0.329, Y=0.600.

7. Change the video test pattern to TP3 (100 IRE Flat Field). Set highlight temperature using the Red and Blue Drives (P:22 and P:23) for x=0.313, y=0.329.

8. Repeat steps 6 and 7 as needed for accuracy

9. Exit the serviceman menu by pressing "INFO" on the remote control.

Conclusion

The purpose of screen control alignment is to match the electronic video signal to the CRT electrical characteristics. In other words, if the video signal requires beam current to stop, the CRT must know that value. Screen control setup is an exact adjustment.

On the other hand, color temperature can be perceived differently depending upon room lighting and environment, original program material, electrical adjustment of the video processing and control circuits and finally, the viewer. What looks red to a technician, may look purple or orange or any other color to another viewer. The technician should strive to provide a "trained" eye by knowing what proper color tracking is. "Color Tracking" itself is a misnomer. Color temperature alignment is actually striving for a uniform gray, with no hint of color tinting, as the ideal for any light output level of the CRT.

Page 3-9

DTV307

ALIGNMENT PROCEDURES (Continued)

Comb D/A Level - Composite (Parameter 32)

1. Apply a 100 IRE (white) signal to the AUX 1 input.

2. Select AUX 1 for the main picture.

3. Connect a scope probe to the negative lead of C22323.

4. Adjust the Comb D/A value (Parameter 32) for 0.71

volts from black (blanking) to white.

Comb D/A Level - SVideo (Parameter 36)

1. Apply a 100 IRE (white) signal to the SVideo input.

2. Select SVideo for the main picture.

3. Connect a scope probe to the negative lead of C22323.

4. Adjust the Comb D/A value (Parameter 32) for 0.71

volts from black (blanking) to white.

PIP Contrast - Composite (Parameter 33)

1. Apply a color bar signal to the AUX 1 input.

2. Select AUX 1 for the main picture.

3. Turn on PIP and select AUX 1 for the PIP picture.

4. Adjust PIP Contrast (Parameter 33) for equal contrast levels between the main picture and the PIP picture.

PIP Tint\Saturation - Composite (Parameters 34, 35)

1. Apply a color bar signal to the AUX 1 input.

2. Select AUX 1 for the main picture.

3. Turn on PIP and select AUX 1 for the PIP picture.

4. Adjust PIP Tint (Parameter 34) for equal tint between the main picture and the PIP picture.

5. Adjust PIP Saturation (Parameter 35) for equal saturation between the main picture and the PIP picture (may affect tint slightly).

6. Repeat steps 4 and 5 until both the tint and saturation level are the same for both pictures.

PIP Contrast - SVideo (Parameter 37)

1. Apply a color bar signal to the SVideo input.

2. Select SVideo for the main picture.

3. Turn on PIP and select SVideo for the PIP picture.

4. Adjust PIP Contrast (Parameter 37) for equal contrast levels between the main picture and the PIP picture.

Geometry Adjustments

The Geometry alignments on this chassis are very critical and must be performed using ChipperCheck®. Even though some of the geometry alignments are available through the front panel service menu, adjustment is not recommended. Alignment in one mode will interact and affect the displays of the other modes.

To perform geometry adjustments a template must be placed on the screen. The grid divides the screen into 6.5 equal squares from right and left to center. It also divides the screen into 5.5 squares from top and bottom to center.

If a template is not available, center screen may be confirmed by placing two strings on the screen. One string is placed on the diagonal from the top left corner to the bottom right. The other is fixed from the top right corner to the bottom left. The intersection of the two lines should be center screen. The outer lines should be just at the frame. All other lines can be measured from center screen and the frame. Chipper Check will provide the measurements depending upon screen size.

For the remainder of the adjustments the grid must be used and the following order FOLLOWED EXACTLY!!!

P12: Do not adjust! P6 is fixed at V:32. P10 is fixed at V:3. P8 is fixed at V:4. P13 is set to V:32 for 2.14H. All other modes the center

horizontal line should intersect at the screen center. P5 is adjusted such that the right border is just inside the

screen frame at point B. P11 is adjusted to place the top border (horizontal line

intersecting point D) is at the upper screen edge. P7 is set to obtain the straightest line between points D and E. P9 is set for the straightest line between points D and E. P11 is re-adjusted (if required) to place the top border

(horizontal line intersecting point D) is at the upper screen edge.

P4 is adjusted after returning normal video to the screen for horizontal centering.

PIP Tint\Saturation - SVideo (Parameters 38,39)

1. Apply a color bar signal to the SVideo input.

2. Select SVideo for the main picture.

3. Turn on PIP and select SVideo for the PIP picture.

4. Adjust PIP Tint (Parameter 33 for equal tint between the main picture and the PIP picture.

5. Adjust PIP Saturation (Parameter 39) for equal saturation between the main picture and the PIP picture (may affect tint slightly).

6. Repeat steps 4 and 5 until both the tint and saturation level are the same for both pictures.

Page 3-10

Figure 1 - Geometry Pattern

DTV307

ALIGNMENT PROCEDURES (Continued)

Yoke Centering Ring Adjustment

If Chipper Check is not available it is possible to replace a single CRT and realign geometry by using the centering rings on the CRT.

Using the convergence pattern available when in service menu V:80, the pattern from the replacement CRT may be adjusted to align with either of the two remaining CRT's using the centering rings shown in Figure 2.

First make certain the replacement CRT is placed back in the mounting as close as possible to the position of the original CRT. At this point having the convergence pattern on screen will assist in the mechanical mounting. Once the CRT assembly is located fasten it securely.

Rotate Tabs Together

Spread Tabs Apart

Centering

SVM Y oke

Phosphor

Screen

Kine

Socket

Figure 2 - Centering Rings

Figure 3 - Centering Ring Tab Movement

Using the centering rings (Figure 3) and observing the convergence pattern, rotate and move the pattern until the replacement color overlays as close as possible to the two colors not replaced. Moving the ring tabs together around the neck of the CRT draws the raster in small circles. Spreading the tabs apart moves the raster in more linear angles. The closer the tabs are together, the less affect on the CRT beam they have.

When the raster is as close as possible fix the magnets with paint or nail polish to prevent further movement.

After fixing the magnets, if gross geometry errors are apparent, geometry alignment is indicated. If the raster is close use the "Auto-convergence" feature provided in the consumer menu to re-align convergence. This should correct most minor geometry problems. Follow auto-convergence with the consumer red and blue centering adjustments, then evaluate the raster again.

In most cases convergence will now be acceptable. If only slight convergence errors are noted the technician should enter the manual digital convergence menu at V:80 and begin "touch-up" of the screen.

If gross geometry errors are still apparent re-evaluate whether the errors are noticable on the replacement CRT or whether they are global, affecting all three c CRT's. If the errors affect all three CRT's a full geometry alignment is indicated. If the errors only affect one CRT, particulary the replacement, return to the mechanical placement and centering ring adjustments and begin those procedures again.

Page 3-11

DTV307

ALIGNMENT PROCEDURES (Continued)

Digital Convergence

There are four security locations associated with digital convergence. Their exact functions will be explained later.

They are: V: 76; The main service alignment location.

Contains the geometry alignments associated with convergence.

V: 80; The main digital convergence location. V: 82; PTV sensor positioning. V: 83; Restore factory Digital Convergence

values. V: 84; Save current alignments.

When the chassis is in service mode and digital convergence is active (V:80) the following remote control functions are enabled:

INFO; Toggles the convergence mode off after

alignments are completed

CH+/CH-; Adjusts the selected alignment point up

or down.

VOL+/VOL-; Adjusts the selected alignment point

right or left.

Cursor Arrow Buttons; Moves the cursor in the

appropriate direction.

SKIP; Toggles the convergence mode through the

following four states. Red to Green: Allows adjustment of red

convergence using the green pattern as a template.

Blue to Green: Allows adjustment of blue convergence using the green pattern as a template.

All: Allows adjustment of the green convergence. Provides a white convergence pattern allowing comparison of the pattern for more accurate results.

Green: Allows adjustment of the green convergence. This should be used only with a mylar template or strings placed on the front screen.

Figure 4 - Main Convergence Screen with Cursor at Center

Convergence Pattern

The convergence pattern displayed when in the digital convergence mode (V:80) appears as in Figure 4. Shown is the cursor at center screen. This is how the convergence pattern appears when the technician initially enters the digital convergence alignment mode.

CAUTION: DO NOT PRESS THE "OFF" BUTTON. THIS WOULD TURN OFF THE SET WITHOUT SAVING THE CONVERGENCE ADJUSTMENTS.

All other buttons are ignored by System Control and the Digital Convergence microprocessor during convergence alignment.

After placing the instrument in service mode, use either the remote control or the front panel button VOL UP to advance the right side screen number (V:) to 80. Then push CH UP. This places the instrument in digital convergence mode.

Page 3-12

DTV307

ALIGNMENT PROCEDURES (Continued)

Convergence Mode

During digital convergence mode, the display will blank incoming video allowing only the digital convergence crosshatch pattern with the cursor at the center location. The initial adjustment is red. Green is fixed. Red and blue will be aligned to green.

The volume and channel buttons will provide adjustment of the selected cursor location up, down, left and right in single steps. The cursor position is indicated by a crosshair. The intersection of the highlighted crosshair is the alignment currently being adjusted. Note only a portion of the crosshair will be seen when it is positioned to adjust the off-screen points along the picture edges. Use the small line segments that extend to the picture edge to adjust these points.

NOTE: In the extreme diagonal positions, the cursor is invisible but the point is still adjustable. Do not adjust these off-screen corner points.

For best results, adjust the pattern beginning at the upper left of the screen. Then continue the adjustments from left to right and top to bottom as if reading a book.

The four navigation "MOVE" buttons adjust the movement of the selected color at the cursor point. They will move the alignment point for the selected color up, down, right or left. Adjust so that it is centered on green with minimum fringing on either side.

The "SKIP” button will toggle the display through 4 states:

Yellow crosshatch, Yellow cursor, Red adjustment, no other OSD or video.

2. Cyan crosshatch, Cyan cursor, Blue adjustment, no other OSD or video.

3. White crosshatch, White cursor, no adjustment available. Used to observe convergence results.

4. Green crosshatch, Green Cursor.

The PWR button returns the receiver to normal operation, however the adjustments are not stored to EEPROM. More on the actual storing of data to the digital convergence EEPROM later.

As previously discussed, there are also four service menu

locations associated with digital convergence. They are:

V: 80; The main digital convergence location.

V: 82; PTV sensor positioning. V: 83; Restore factory Digital Convergence

values. V: 84; Save current alignments.

V:80 is the main digital convergence menu. It contains an "all-points" adjustment procedure very much like the CTC195. When convergence alignments are complete, the technician exits this menu by pressing "On/Off" on the remote control or "Power" on the front panel. Convergence alignments for the selected scan mode are stored in the current mode EEPROM at this point and will be used until they are changed during the next menu V:80 alignment procedure or the consumer accesses the "Auto-Convergence" procedure. In that case, the original factory alignment data will be placed back into the EEPROM and the screen aligned to the faulty data.

To prevent this, once alignments are complete for the selected mode, the service menu must be entered again, this time V:84 will be selected. At V:84, press CH UP. This transfers the new alignment data for the selected deflection mode to the factory EEPROM. Then the service menu is decremented to V:82 and CH UP is again pressed. This starts a routine to allow the optical sensors located on the screen frame to "memorize" the new alignment data. It looks similar to the consumer "Auto-convergence" procedure. Once the routine is completed "Auto-convergence" will function correctly, returning the screen to the convergence setup by the technician. This new data becomes the "factory default" data from this point forward, only changing if a new set of alignments is placed into the EEPROM using the same procedure.

Menu V:83 performs the same convergence routine as selecting "Auto-convergence" from the consumer menu.

Digital Convergence Alignment Overview

There are four convergence modes in the DTV307 corresponding to the four deflection (scan) modes. Each requires complete convergence alignment and stores the alignment points in separate EEPROMS. There is also another EEPROM containing convergence data installed at the time of manufacture. It is always available to allow a "starting" point in cases where catastrophic failure of convergence data has occured. This EEPROM is larger than the others and contains reference data for all four scan modes.

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BLOCK DIAGRAM

SCLM SDAM

SCLS SDAI SDAO ADS0

OSCL GRES

ECLK FILT

FLT2 SYNH

SYNV

REST

TEST

I2C

Master

I2C

Slave

Oscillator

PLL

SYS_CLK

Filter

Reset

Controller

Digicon III

RAM

Controller

Bus

Controller

Horizontal

Timebase

Vertical

Video DACs

Interpolation

Registers

D0...E2

Registers

E3...EE

Video Pattern

Generator

RGB

Registers

Timing

Gain Range

Control

Electrical

Loop

OPT

Port

dig.

Filter

dig.

Filter

Convergence

DACs

Focus

Processor

I/O Ports

Bandgap

Focus

DAC

DARH DNRH DAGH

DNGH

DABH

DNBH

DARV DNRV DAGV DNGV

DABV

DNBV

REFN

REFC

POUT

DACF

DNCF

MLIN

VIDB

VIDR

VIDG

OPTI

VBLK

OPTT

PORA

PORB

PORC

OGAH

TBU0

TBU1

TBU2

TBU3

TBU4

TBU5

TBU6

OGAV

TBU7

DTV307

CIRCUIT OVERVIEW

AC IN

Three line chokes in series and capacitors across the outputs are used to provide Line Conducted Interference (LCI) suppression to the AC line. A full wave bridge is connected to the 60Hz ac line to provide Raw B+ to both the standby Zero Voltage Switching (ZVS) circuit and the main high power isolat ing regulator.

A provision for a Negative Temperature Coefficient Resistor (NTC) RT14202 may be used as a surge current resistor to c ontrol inrush curre nt through the diod es as the main electrolytic charges initially to minimize power and temperature.

Grounding of the 3-wire line cord is to the metal mechanical structure to which the main spark gap and audio/video grounds are connected.

Main Run Power Supply

Main Run Power Supply Operation

The main run power supply circuit operates in the Zero Voltage Switching (ZVS) mode to minimize radiated noise and to improve efficiency.

A high power output, single switch power supply requires a switching device that has a high curre nt rating and high breakdown voltage. The most cost-effective type of device for this application is a bipolar switching transistor, but bipolar transistor require a significant amount of base current drive in the forward direction, and even higher level of current during turn-off to ensure fast switching.

A simple proportional drive circuit that also provides a self-oscillating capability has been developed for the DT30X family. Proportional drive is advantageous

because it provides a relatively constant ratio of base current to collector current. This constant ratio prevents the switching transistor base from being overdriven in the forward direction during low current operation, thus improving the switching speeds. Proportional drive also provides increased base drive when high peak current is required from the switching transistor to ensure proper saturation to minimize power dissipation. This circuit operates in the forward mode because of the high power output requirements, providing energy to the secondary windings during the main switch cond uction interval. I n this implementation the primary winding of T14101, provides the means for the energy stored in the resonant inductor to be transferred to the output while the switching transistor is on.

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DTV307

CIRCUIT OVERVIEW

A high current latch provides a low impedance path for reverse base current to flow during turn-off. The latch is made up of Q14101 and Q14103 a PNP/NPN transistor pair. A negative bias on the base of the switching transistor, Q14100, is provided by the drive transformer, a series Zener diode, CR14105, and bypass capacitor, C14103, to improve reliability and switching speeds.

Oscillation is initiated by current flowing from a high value resistor R14103 connected to the Raw B+. It causes a small amount of base current to flow in the main power switch Q14100. A drive transformer T14101 is connected as a current transformer and causes current to flow in the secondary winding in response to the current flow in the primary winding. The ratio of primary current to secondary current is determined by the turns ratio of the drive transformer, about 7 to 1. Since additional current begins to flow in the base of the switching transistor from the secondary of T14101, additional current will flow in the primary and a regenerative effect will take place causing the system to self oscillate. The expected range of switching frequency is 80kHz to 120 kHz.

Switch Mode transistor current is sensed by an emitter resistor, R14100; the developed voltage is fed to the NPN/PNP latch. When the voltage across R14100 increases the base of Q14103 becomes sufficiently positive to cause it to turn-on. Current flowing in Q14103 causes Q14101 to turn-on diverting base current away from the Q14100 and latching Q14103. CR14105 and C14103 provide a negative voltage feedback to the base of Q14100 to improve the turn off characteristics of the main power switch.

a current path of the forward drive current and limits the voltage to which C14104 can charge. A negative base bias voltage is coupled to Q14100 through C14104 to Q14100 when it is in the off state. Diode CR14117 and C14121 bias and rectify and filter the negative voltage developed from the drive transformer, T14101, to provide a negative supply voltage for the control circuit.

A feedback signal from an error amplifier that senses the output voltage of the supply drives an opto-coupler with a variable current. The +76V supply is sensed via a resistor divider and fed to the reference IC U14101. As the output voltage increases above the threshold set by the error amplifier, the current through the diode portion of the opto-coupler increases causing increasing current to flow in the transistor portion. This increased current flow causes the voltage across C14112 to drop which in turn lowers the threshold at which Q14103 will begin to conduct, lowers the peak current in the switching device, and reduces the output voltage of the system until equilibrium is established.

Overcurrent Protection

When an overload appears, the current through (and the voltage across) the sense resistors approaches a sawtooth shape with nearly equal positive and negative amplitudes. The negative-going portion of this voltage is passed by CR14122 and lowers the voltage on the emitter of Q14103 that in turn lowers the maximum peak current that can flow through the transistor.

Standby Power Operation

Diode CR14108 and resistor R14117 shunt some of the reverse base current to the low impedance of the current sense resistor. This shunting effect prevents the overstressing the base of Q14103.

Q14102 and Q14103 remain latched until the current flowing through the pair drops below the latching threshold. The negative voltage produced by T14101 keeps the main switch mode transistor from conducting until the resonant action of the resonating inductor and the resonant capacitor, C14113, causes the voltage to reverse. As the voltage at the base of Q14100 rises, current begins to flow and the next cycle begins.

When Q14100 turns off, the collector voltage begins to rise but the voltage change is limited by the resonance effect produced by L14103 and C14113. Because Q14100 turns off very rapidly, very little power is dissipated since the collector voltage remains low during the turn-off interval. When the collector voltage of Q14100 resonates toward ground, the collector-base junction conducts and diode CR14128 provides a path for the resonant current returning to the Raw B+ supply after the resonant cycle is complete. Diode CR14115 provides

The standby power supply uses a ZVS circuit similar to the main run circuitry. It uses a flyback topology rather than the forward mode of the main power supply. A MOSFET, Q14601, serves as the switching device with the energy storage components the primary inductance of T14600 and the resonating capacitor, C14605.

+5VFB is sampled and regulated directly via the reference IC U14603 and opto-coupler, U14601. A transistor switch Q14604 is enabled by the +12v run in order to shed load in the standby mode.

An isolated supply (+8V_USB) provides the source for the USB 5v regulator that is located on the I/O board.

Provisions ha ve been made for powering a tuner with the +15vs, +33vs and -12vs. The +33vs is switched on by the +12vr.

On sets supporting GemStar99, a 9VS standby source is provided from +15VS via a dropping resistor to form an unregulated +12VS. This supply is fed to a switched +9V

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