Sharp 21FL84 Service Manual

21FL84

SERVICE MANUAL

COLOR TELEVISION

Chassis No. GA-4

MODEL

In the interests of user-safety (Required by saf ety regulations in some countries ) the set should be restored to its original condition and only parts identical to those specified should be used.

CONTENTS

» ELECTRICAL SPECIFICATIONS .........................................................................................................1

» IMPORTANT SERVICE SAFETY PRECAUTION .................................................................................2

» LOCATION OF USER'S CONTROL .....................................................................................................4

» INSTALLATION AND SERVICE INSTRUCTIONS................................................................................5

» SERVICE MODE ..................................................................................................................................6

» ADJUSTMENT METHOD...................................................................................................................12

» CHASSIS LAYOUT................................................................................................................................15

» BLOCK DIAGRAM..............................................................................................................................16

» DESCRIPTION OF SCHEMATIC DIAGRAMS & WAVEFORMS........................................................19

» SCHEMATIC DIAGRAMS...................................................................................................................20

» PRINTED WIRING BOARD ASSEMBLIES........................................................................................23

» REPLACEMENT PARTS LIST............................................................................................................26

» PACKING OF THE SET......................................................................................................................31

21FL84

Page

ELECTRICAL SPECIFICATIONS

POWER INPUT....................................... AC 110~220 V, 50/60 Hz

POWER RATING....................................................................88W

PICTURE SIZE .......................................... 1,239 cm2 (192sq inch)

CONVERGENCE ............................................................. Magnetic

SWEEP DEFLECTION .................................................... Magnetic

FOCUS .................................................. QFP/UNI-B1 Electrostatic

INTERMEDIATE FREQUENCIES

Picture IF Carrier Frequency ..................................... 45.75 MHz

Sound IF Carrier Frequency...................................... 41.25 MHz

Color Sub-Carrier Frequency .................................... 42.17 MHz

(Nominal)

AUDIO POWER

OUTPUT RATING........................................3.0 W(RMS) x 2pcs

SPEAKER

SIZE ...................................................................12 x 5 cm, 2pcs

VOICE COIL IMPEDANCE............................. 16 ohm at 400 Hz

ANTENNA INPUT IMPEDANCE

VHF/UHF.....................................................75 ohm Unbalanced

TUNING RANGES

VHF-Channels...............................................................2 thru 13

UHF-Channels ............................................................14 thru 69

CATV Channels ...........................................................1 thru 125

(EIA, Channel Plan U.S.A.)

Specifications are subject to change without prior notice.

SHARP CORPORATION

This document has been published to be used for after sales service only. The contents are subject to change without notice.

21FL84

IMPORTANT SERVICE SAFETY PRECAUTION

Service work should be performed only by qualified service technicians who are thoroughly familiar with all safety checks and the servicing guidelines which follow:

WARNING

1. For continued safety, no modification of any circuit should be attempted.

2. Disconnect AC power before servicing.

3. Semiconductor heat sinks are potential shock hazards when the chassis is operating.

4. The chassis in this receiver has two ground systems which are separated by insulating material. The nonisolated (hot) ground system is for the B+ voltage regulator circuit and the horizontal output circuit. The isolated ground system is for the low B+ DC voltages and the secondary circuit of the high voltage transformer. To prevent electrical shock use an isolation transformer between the line cord and power receptacle, when servicing this chassis.

SERVICING OF HIGH VOLTAGE SYSTEM AND PICTURE TUBE

When servicing the high voltage system, remove the static charge by connecting a 10k ohm resistor in series with an insulated wire (such as a test probe) between the picture tube ground and the anode lead. (AC line cord should be disconnected from AC outlet.)

1. Picture tube in this receiver employs integral implosion protection.

2. Replace with tube of the same type number for continued safety.

3. Do not lift picture tube by the neck.

4. Handle the picture tube only when wearing shatterproof goggles and after discharging the high voltage anode completely.

X-RADIATION AND HIGH VOLTAGE LIMITS

1. Be sure all service personnel are aware of the procedures and instructions covering X-radiation. The only potential source of X-ray in current solid state TV receivers is the picture tube. However, the picture tube does not emit measurable X-Ray radiation, if the high voltage is as specified in the "High Voltage Check" instructions. It is only when high voltage is excessive that Xradiation is capable of penetrating the shell of the picture tube including the lead in the glass material. The important precaution is to keep the high voltage below the maximum level specified.

2. It is essential that servicemen have available at all times an accurate high voltage meter. The calibration of this meter should be checked periodically.

3. High voltage should always be kept at the rated value

−no higher. Operation at higher voltages may cause a failure of the picture tube or high voltage circuitry and;also, under certain conditions, may produce radiation in exceeding of desirable levels.

4. When the high voltage regulator is operating properly there is no possibility of an X-radiation problem. Every time a color chassis is serviced, the brightness should be tested while monitoring the high voltage with a meter to be certain that the high voltage does not exceed the specified value and that it is regulating correctly .

5. Do not use a picture tube other than that specified or make unrecommended circuit modifications to the high voltage circuitry.

6. When trouble shooting and taking test measurements on a receiver with excessive high voltage, avoid being unnecessarily close to the receiver. Do not operate the receiver longer than is necessary to locate the cause of excessive voltage.

IMPORTANT SERVICE SAFETY PRECAUTION

DVM

AC SCALE

1.5k ohm 10W

TO EXPOSED METAL PARTS

CONNECT TO KNOWN EARTH GROUND

(Continued)

21FL84

BEFORE RETURNING THE RECEIVER (Fire & Shock Hazard)

Before returning the receiver to the user, perform the following safety checks.

1. Inspect all lead dress to make certain that leads are not pinched or that hardware is not lodged between the chassis and other metal parts in the receiver.

2. Inspect all protective devices such as non-metallic control knobs, insulating materials, cabinet backs, adjustment and compartment covers or shields, isolation resistor-capacity networks, mechanical insulators, etc.

3. To be sure that no shock hazard exists, check for leakage current in the following manner.

• Plug the AC cord directly into a 110~220 volt AC outlet, (Do not use an isolation transformer for this test).

• Using two clip leads, connect a 1.5k ohm, 10 watt resistor paralleled by a 0.15µF capacitor in series with all exposed metal cabinet parts and a known earth ground, such as electrical conduit or electrical ground connected to earth ground.

• Use an AC voltmeter ha ving with 5000 ohm per volt, or higher, sensitivity to measure the A C v oltage drop across the resistor.

• Connect the resistor connection to all exposed metal parts having a return to the chassis (antenna, metal cabinet, screw heads, knobs and control shafts, escutcheon, etc.) and measure the AC voltage drop across the resistor. AII checks must be repeated with the AC line cord plug connection reversed. (If necessary, a nonpolarized adapter plug must be used only for the purpose of completing these check.) Any current measured must not exceed 0.5 milliamp. Any measurements not within the limits outlined above indicate of a potential shock hazard and corrective action must be taken before returning the instrument to the customer.

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SAFETY NOTICE

Many electrical and mechanical parts in television receivers have special safety-related characteristics. These characteristics are often not evident from visual inspection, nor can protection afforded by them be necessarily increased by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in this manual; electrical components having such features are identified by "å" and shaded areas in the Replacement Parts Lists and Schematic Diagrams.

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For continued protection, replacement parts must be identical to those used in the original circuit. The use of substitute replacement parts which do not have the same safety characteristics as the factory recommended replacement parts shown in this service manual, may create shock, fire, X-radiation or other hazards.

21FL84

LOCATION OF USER'S CONTROL

Front Panel

POWER

Press → On. Press again

SENSOR AREA FOR REMOTE CONTROL

Press Press again

→ Off.

→ Accesses MAIN MENU.

→ Exits MAIN MENU.

VOLUME UP/DOWN

(+) Increases sound. (

) Decreases sound.

Basic Remote Control Functions

POWER

Press → On. Press again → Off.

REMOTE KEYPAD

Accesses any channel from keypad.

FLASH BACK

Returns to previous channel.

VOLUME UP/DOWN

(+) Increases sound. (–) Decreases sound.

• In menu mode, changes or selects the TV adjustments.

MUTE

Press Mutes sound. Press again Restores sound.

• CLOSED CAPTION appears when

sound is muted.

VIDEO IN 2 L-AUDIO-R

(INSIDE DOOR)

CHANNEL UP/DOWN

(') Selects next higher channel.

) Selects next lower channel.

(

Infrared Transmitter Window

INPUT Press → Switch to external video input mode. Press again → Switch to TV mode.

CHANNEL UP/DOWN

(8) Selects next higher channel. (9) Selects next lower channel.

• Moves the “ ” mark of the MENU

screen.

Press →

Accesses MAIN MENU.

Press again →

DISPL AY

Press → Displays receiving channel for 4 seconds. Press again → Removes display.

• Temporarily displays receiving channel when in Closed Caption mode.

Exits MAIN MENU.

Note:

The above shaded buttons on the Remote Control glow in the dark. To use the glow-in-the-dark display on the remote control, place it under a fluorescent light or other lighting. The phosphorescent material contains no radioactive or toxic material, so it is safe to use. The degree of illumination will vary depending on the strength of lighting used. The degree of illumination will decrease with time and depending on the temperature. The time needed to charge the phosphorescent display will vary depending on the surrounding lighting. Sunlight and fluorescent lighting are the most effective when charging the display.

21FL84

INSTALLATION AND SERVICE INSTRUCTIONS

Note: (1) When performing any adjustments to resistor controls and transformers use non-metallic

screwdrivers or TV alignment tools.

(2)Before performing adjustments, the TV set must be on at least 15 minutes.

CIRCUIT PROTECTION

The receiver is protected by a 3.15A fuse (F701), mounted on PWB-A, wired into one side of the AC line input.

X-RADIATION PROTECTOR CIRCUIT TEST

After service has been performed on the horizontal deflection system, high voltage system, B+ system, test the X-Radiation protection circuit to ascertain proper operation as follows:

1. Apply 110~220V AC using a variac transformer for accurate input voltage.

2. Allow for warm up and adjust all customer controls for normal picture and sound.

3. Receive a good local channel.

4. Connect a digital voltmeter to P603 pin3 and make sure that the voltmeter reads 20 ±1.1V.

5. Apply external 27V DC at P603 pin3 by using an external DC supply, TV must be shut off.

6. To reset the protector, unplug the AC cord and mak e a short circuit between P603 pin1 and P603 pin2. Now make sure that normal picture appears on the screen.

7. If the operation of the horizontal oscillator does not stop in step 5, the circuit must be repaired before the set is returned to the customer.

HIGH VOLTAGE CHECK

High voltage is not adjustable but must be checked to verify that the receiver is operating within safe and efficient design limitations as specified checks should be as follows:

1. Connect an accurate high voltage meter between ground and anode of picture tube.

2. Operate receiver for at least 15 minutes at 110~220V AC line voltage, with a strong air signal or a properly tuned in test signal.

3. Enter the service mode and set Y-mute ON by using Service R/C.

4. The voltage should be approximately 28.7kV (at zero beam). If a correct reading cannot be obtained, check circuitry for malfunctioning components. After the v oltage test, make Y-mute off to the normal mode.

21FL84

SERVICE MODE

Service Mode Overview

1. Service mode is entered by SERVICE key input or CH-UP +VOL-DOWN input during reset.

2. Service mode is cleared by entering SERVICE key command during service mode.

3. If key input port (SERVICE) input is LOW, then it is in service mode.

4. During key input port (SERVICE) input is LOW, clearing service mode by key input SERVICE is disabled.

5. Service mode can be switched to 4 modes as follows by key input MENU;

Adjustment mode

Setting mode

Check mode

Option mode

6. AFT processing is disabled during service mode. PLL setting data is set to fo data.

7. All user data are set to default during service mode. FAO and SPEAKER user settings are off and on respectively in service mode. Energy Save is off.

8. Sleep timer, View timer, on timer and off timer are inactivated in Service mode.

9. Sound is muting in service mode except at Adjustment Items V20, M01, M03, M04, M05, and M06.

First mode of service mode when SERVICE key is pressed.

First mode of service mode when local key CH-UP + VOL-DOWN is pressed after MCU reset.

Adjustment Mode Items

No. Item Name IC Register Range Default

V01SUB-PICTURE1 ChipCONTRAST0~127127 V02SUB-TINT1 ChipTINT0~12764 V03SUB-COLOR1 ChipCOLOR0~12764 V04SUB-BRIGHT1 ChipBRIGHT0~255128 V05 SUB-SHARP 1 Chip VIDEO-TONE 0~63 32 V06 V-SHIFT 1 Chip V-SHIFT 0~7 4 V07H-SHIFT1 ChipH-PHASE0~3116 V08RF-AGC1 ChipRF-DELAY0~127127 V09 V-SIZE 1 Chip V-SIZE 0~63 32 V10 PIF-VCO 1 Chip VIF-VCO 0~63 32 V11R-CUTOFF1 ChipR-CUTOFF0~255 64 V12G-CUTOFF1 ChipG-CUTOFF0~255 64 V13B-CUTOFF1 ChipB-CUTOFF0~255 64 V14R-DRIVE1 ChipR-DRIVE0~12764 V15B-DRIVE1 ChipB-DRIVE0~12764 V16SUB-COLOR(YUV)1 ChipCOLOR0~12764 V17SUB-TINT(YUV)1 ChipBASEBAND-TINT0~12764 V18CC-POSMICONCC-POS0~25532 V19SCREEN CUT OFF1 ChipCUT OFF0~20 V20SUB-VOL1 ChipA-ATT0~127127

V21 H-VCO 1 Chip H-VCO 0~7 4 M01MTS-ATTMTSATT (MTS)0~1516 M02MTS-VCOMTSVCO (MTS)0~6332 M03 MTS-FILTER MTS FILTER (MTS) 0~63 28 M04 MTS-WIDEBAND MTS WIDEBAND (MTS) 0~63 27 M05 MTS-SPECTRAL MTS SPECTRAL (MTS) 0~63 32 M06 SUB-VOL MTS VOL (MTS) 0~63 63

21FL84

SELF ADJUSTMENT

H-VCO

1. When there is H-VCO self-adjustment key input for adjustment item H-VCO, self-adjustment is performed.

2. H-FREE(1chip) is set to 1.

3. H-OUT is set by intelligent monitor output.

4. IM input is set as TIM input.

5. H-VCO(1chip) data is changed so that the number of input pulse is 125 inside 8ms interval.

6. When adjustment completed, OSD display and H-VCO self-adjustment status data of EEPROM are updated.

7. H-FREE(1chip), intelligent monitor output and IM input mode are recovered.

RF-AGC

1. When there is RF-AGC self-adjustment key input for adjustment item RF-AGC, self-adjustment is performed.

2. AGC-OUT is set by intelligent monitor output.

3. IM input is set as AD input.

4. By decreasing RF-AGC (1chip) data from current RF-AGC adjustment value to 0, AFT input voltage becomes the maximum setting value.

5. Increase RF-AGC(1chip) data, when AFT input voltage is at (max. 0.3V) point, adjustment is completed.

6. When adjustment completed, OSD display and RF-AGC self-adjustment status data of EEPROM are updated.

7. Intelligent monitor output and IM input mode are recovered.

PIF-VCO

1. When there is PIF-VCO self-adjustment key input for adjustment item PIF-VCO, self-adjustment is performed.

2. VIF-DEF(1chip) is set to 1.

3. AFC is set by intelligent monitor output.

4. IM input is set as AD input.

5. VIF-VCO(1chip) data is changed so that input voltage becomes 2.5V.

6. When adjustment completed, OSD display and PIF-VCO self-adjustment status data of EEPROM are updated.

7. VIF-DEF(1chip), intelligent monitor output and IM input mode are recovered.

Setting Mode Items

No. Item Name IC Register Range Default

F01 VIDEO TONE -GAIN (TV) 1 Chips V-TONE 0/1 0 F02 VIDEO TONE -GAIN (AV) 1 Chips V-TONE 0/1 0 F03

VIDEO TONE -GAIN (S-AV) F04 VIDEO TONE -GAIN(YUV) 1 Chips V -T ONE 0/1 0 F05 ABCL 1 Chips ABCL 0/1 0 F06 BS 1 Chips BS-OFF 0/1 0 F07 ABCL-G 1 Chips ABCL-G 0/1 0 F08 SHP-AV OFFSET VIDEO-TONE(OFFSET) -16~+16 0 F09 SHP-SAV OFFSET VIDEO-TONE(OFFSET) -16~+16 0 F10 SHP-YUV OFFSET VIDEO-TONE(OFFSET) -16~+16 0 F11 RGB-CLIP 1 Chips EXTRGB-CLIP 0/1 0 F12 E-SAVE OFFSET CONTRAST(OFFSET) 0~63 30 F13 FAO-VOL 1 Chips A-ATT 0~127 120 F14 PIF-G 1 Chips VIF-GAIN 0~7 4 F15 Y-DELAY(TV) 1 Chips Y-DELAY 0~7 0 F16 Y-DELAY(AV) 1 Chips Y-DELAY 0~7 0 F17 Y-DELAY(SAV) 1 Chips Y-DELAY 0~7 0 F18 Y-DELAY(YUV) 1 Chips Y-DELAY 0~7 0 F19 TINT-AV OFFSET TINT(OFFSET) -32~+32 0 F20 TINT-SAV OFFSET TINT(OFFSET) -32~+32 0 F21 COL-AV OFFSET COLOR(OFFSET) -32~+32 0 F22 COL-SAV OFFSET COLOR(OFFSET) -32~+32 0 F23 R-DRI(R2) OFFSET R-DRI(OFFSET) -32~+32 0 F24 R-DRI( R) OFFSET R-DRI(OFFSET) -32~+32 0 F25 R-DRI(B) OFFSET R-DRI(OFFSET) -32~+32 0 F26 B-DRI(R2) OFFSET B-DRI(OFFSET) -32~+32 0 F27 B-DRI( R) OFFSET B-DRI(OFFSET) -32~+32 0 F28 B-DRI(B) OFFSET B-DRI(OFFSET) -32~+32 0 F29 V-FREE 1 Chips V-FREE 0/1 0 F30 GAMMA 1 Chips GAMMA 0~3 0 F31 TRAP(TV) 1 Chips TRAP-FINE 0~3 2 F32 TRAP(AV) 1 Chips TRAP-FINE 0~3 2 F33 H-FREE 1 Chips H-FREE 0/1 0 F34 1W(TV) 1 Chips V.WINDOW 0/1 0 F35 1W(AV) 1 Chips V.WINDOW 0/1 0 F36 YLPF 1 Chips YSW-LPF 0/1 1 F37 BS-D 1 Chips BS-DISCHARGE 0~3 0 F38 BS-C 1 Chips BS-CHARGE 0~3 0 F39 SL(TV) 1 Chips S-SLICE DOWN 0~3 0 F40 SL(AV) 1 Chips S-SLICE DOWN 0~3 0 F41 SL(SAV) 1 Chips S-SLICE DOWN 0~3 0 F42 SL(YUV) 1 Chips S-SLICE DOWN 0~3 0 F43 AFC2 1 Chips AFC2-G 0/1 0 F44 VD(TV) 1 Chips VSYNC-DET 0/1 0 F45 VD(AV) 1 Chips VSYNC-DET 0/1 0 F46 AS(TV) 1 Chips AUTO-SLICE 0/1 0 F47 AS(AV) 1 Chips AUTO-SLICE 0/1 0 F48 AS(SAV) 1 Chips AUTO-SLICE 0/1 0 F49 AS(YUV) 1 Chips AUTO-SLICE 0/1 0 F50 FBP(TV) 1 Chips FBP VTH 0/1 0 F51 FBP(AV) 1 Chips FBP VTH 0/1 0 F52 FBP(SAV) 1 Chips FBP VTH 0/1 0 F53 FBP(YUV) 1 Chips FBP VTH 0/1 0 F54 C.CLIP LEVEL 1 Chips C.CLIP LEVEL 0/1 0

1 Chips V-TONE 0/1 0

21FL84

Setting Mode Items (Continued)

No. Item Name IC Register Range Default

F55 PSW MTS PSW 0/1 0 F56 FAO-VOL MTS VOL 0~63 60 F57 CP PLL CHARGE PUMP 0/1 0 F58 CC LEVEL MICON CC LEVEL 0/1 0 F59 OSD POS MICON OSD POS 0/1 0 F60 OFFSET-ADJ-COL 1 Chips COLOR -32~+32 0 F61 OFFSET-ADJ-TINT 1 Chips TINT -32~+32 0 F62 OFFSET-ADJ-TINT-YUV 1 Chips BASEBAND-TINT -32~+32 0 F63 TIMER4-LOW SPEED 1 Chips TIMER4 VALUE 0~225 50 F64 TIMER4-HIGH SPEED 1 Chips TIMER4 VALUE 0~225 125 F65 R-CUT-YUV 1 Chips R-CUT(OFFSET) -63~+63 0 F66 G-CUT-YUV 1 Chips G-CUT(OFFSET) -63~+63 0 F67 B-CUT-YUV 1 Chips B-CUT(OFFSET) -63~+63 0 F68 R-DRI-YUV 1 Chips R-DRI(OFFSET) -63~+63 0 F69 B-DRI-YUV 1 Chips B-DRI(OFFSET) -63~+63 0 F70 CLOCK-ADJ 1 Chips 0~25 25

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