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CTV2000 08 20 TELEVISION TECHNICAL BULLETIN
MODELS 56FW53H 76FW54H 66FW53H 59ESD7H Month of Issue: September 2000 Classification: White Page 1 of 9
66FW54H 66ESD7H
76FW53H
Faults experienced on the DA100 (50Hz) Chassis The following faults have been experienced on the DA100 (50Hz) chassis (see models listed above). When servicing any model fitted with a FW chassis, ensure that the internal speakers are connected. 1. Fault finding flow chart. (See page 2) 2. LED fault code table (See page 4) 3. NVM associate problems. (See page 5) RGB brightness Green LED ON permanently Low contrast Teletext problem 4. Set may not turn on, when it does there is a rainbow effect on the screen. (See page 7) 5. Very high HT in excess of 200V. (See page 8) 6. Field fold over at the bottom of the screen after about fifteen minutes. (See page 9)
Sharp Electronics (UK) Limited
Revision 1
White Carry out as required Yellow Carry out as required and whenever the unit comes in for service Red Carry out on all units
DA50 Chassis
Fl
Chart 1 - No 140v rail Before switching on ensure that the aerial is not connected
CTV not faulty CTV not faulty standby mode standby mode
Power Supply Starts
Neon illuminated
No
Plug or Internal fuse has failed Plug or Internal fuse has failed Check Bridge Rectifier,Q701, Q702, Check Bridge and D712 Q703 Rectifier,Q701, Q702, Q703 and D712
Yes
Power Supply Starts For A Few Seconds Only
Press CH+ button on main PWB
No
NICAM or OPC LED's illuminated
Yes
Power supply is working correctly Power supply is working correctly check data communication check data communication (see LED's Fault code table) (see LED's Fault code table)
No Change 140v
IC702 pin15 = 0v
Yes
line Drive Missing line Drive Missing go to chart 2 go to chart 2
Between 20 And 40 Volts
Remove R623
No
Check HT (D720 Cathode)
Short circuit on a supply other Short circuit on a supply other than the main HT than the main HT
Zero
Power supply in standby mode Power supply in standby mode check IC702 check IC702
Note:
Short Circuit
An avalanche diode has been added across C720
HT has increased HT has increased replace IC705 and check replace IC705 and check associated components associated components
No
Protection circuit operating Protection circuit operating Check IC1001 pin 95 Check IC1001 pin 95 (5v = Normal\zero= standby) (5v = Normal\zero= standby)
Power Supply not working Power Supply not working Replace R713 and R714 Replace R713 R714 check D712, Q702 and Q703 check D712, Q702 and Q703
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Sharp Electronics (UK) Ltd
DA50 Chassis
Fl
Chart 2 - 140v rail Present Before switching on ensure that the aerial is disconnected
Line Drive Fault Line Drive Fault Check Q607 (crow bar) Check Q607 (crow bar) and IC801 and IC801
Less Than1.8v
EHT Protection circuit operating EHT Protection circuit operating Check D617 and amplitude of the line fly-back pulse Check D617 and amplitude of the line fly-back pulse
More Than 1.8v
Check IC801 pin 12
NICAM or OPC LED's illuminated
Yes
RGB output Fault RGB output Fault Check IC801 Check IC801
Power supply is working correctly Power supply is working correctly check data communication check data communication (see LED's Fault code table) (see LED's Fault code table)
No
No
No LT supply to RGB output No LT supply to RGB output Q902 and associated Q902 and associated components components
Low
Check IC1801 pin 2 12v
Check Line drive IC801 pin 50
No
Check OSD
Yes
No Video No Video Check Video input selection Check Video stage selection and IF input and IF stage
Yes
Correct Waveform
Check IC801 pin 11
(see waveform)
Incorrect Waveform
Increase Screen control
No Vertical Scan
Vertical Output Fault Vertical Output Fault Ensure IC501 pin 12 = 5v Ensure IC501 pin 12 = Check IC501 +/- supply 5v Check IC501 +/- supply
Reduced Vertical Scan
Vertical Flyback fault Vertical Flyback fault Check R530,Q502,Q503,Q507 Check R530,Q502,Q503,Q507 and D507 and D507
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Sharp Electronics (UK) Ltd
CTV2000 08 20 TELEVISION TECHNICAL BULLETIN
Month of Issue: September 2000 Classification: White Page 4 of 9
LED Fault Code Table
LED Fault Main reset or EPROM NVM's MSP Video I2C 1 Locked I2C 2 Locked Mega Text/M3 bus Boot Sequence Green Orange NICAM OPC off 2 Flashes/Pause 3 Flashes/Pause 4 Flashes/Pause Keeps repeating the boot sequence On On On 1 Flash/Pause (1:3) Green - On Green - On Green - Off Orange - on Orange - off Orange - off
Notes
Boot sequence can repeat six times before the fault code is shown Time taken for re-boot will vary depending on which section is faulty
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Sharp Electronics (UK) Limited
Reference AM20092000-1 Revision 1
White Carry out as required Yellow Carry out as required and whenever the unit comes in for service Red Carry out on all units
CTV2000 08 20 TELEVISION TECHNICAL BULLETIN
Month of Issue: September 2000 Classification: White Page 5 of 9
SYMPTOM In some instances, when a RGB signal is applied to the EURO-SCART socket, the brightness varies with picture content. CAUSE ACTION Incorrect black level clamping. Adjust NVM data on page 0D, position 0C from 73 to 57.
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SYMPTOM Set fails to start, green LED stays on permanently. Only one burst of activity on the NVM I2C bus. CAUSE ACTION Serial data problem. Remove the NVM (IC1003) and turn the set on. If the LED gives two flashes, this means that there is no NVM data and that the processor and OTP are working correctly. This probably means that the NVM is faulty. REF NO IC1003 DESCRIPTION IC, NVM PART NUMBER RH-IX1603BMZZ PRICE CODE AV
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SYMPTOM Low contrast, but when the test mode is entered, it returns to normal. CAUSE ACTION NVM corrupted. Adjust G2 as described on the following page. NB. If the fault does not clear, replace the NVM. REF NO IC1003 DESCRIPTION NVM PART NUMBER RH-IX1603BMZZ PRICE CODE AV
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Sharp Electronics (UK) Limited
Reference JC121199-1 JC29062000-3 JC31032000-1 Revision 1
White Carry out as required Yellow Carry out as required and whenever the unit comes in for service Red Carry out on all units
CTV2000 08 20 TELEVISION TECHNICAL BULLETIN
Month of Issue: September 2000 Classification: White Page 6 of 9
SYMPTOM After changing the NVM (or possibly due to data corruption), the half page text appears in the wrong part of the screen - too far left or right.
CAUSE ACTION
Corruption of NVM memory. Enter the service mode and change the following NVM position to the value shown. Page: Position: Value: 00 68 36
Note: To enter the service mode, take the following steps. 1. 2. 3. 4. 5. Turn the set on and ensure that a picture is being displayed. Turn the set off using the mains switch. Press the volume down and channel up buttons on the front of the set. Keeping the buttons pressed, turn the set on using the mains switch. Release the buttons when the service mode is displayed.
Use the channel buttons to move between functions, the volume buttons to change values and the standby button to store.
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Sharp Electronics (UK) Limited
Reference JR29062000-1 Revision 1
White Carry out as required Yellow Carry out as required and whenever the unit comes in for service Red Carry out on all units
CTV2000 08 20 TELEVISION TECHNICAL BULLETIN
Month of Issue: September 2000 Classification: White Page 7 of 9
SYMPTOM Set may not turn on, when it does there may be a rainbow effect on the screen. Note the NICAM LED may be on. CAUSE ACTION Low voltage on IC501 pin 12 (standby/mute). Replace IC501.
REF NO IC501
DESCRIPTION Amplifier
PART NUMBER VHITDA7480/-1
PRICE CODE AK
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Sharp Electronics (UK) Limited
Reference AM191199-1 Revision 1
White Carry out as required Yellow Carry out as required and whenever the unit comes in for service Red Carry out on all units
CTV2000 08 20 TELEVISION TECHNICAL BULLETIN
Month of Issue: September 2000 Classification: White Page 8 of 9
SYMPTOM Very high HT (in excess of 200V) leading to failure of C720. Note that the set may trip in the fault condition.
CAUSE ACTION
No power supply feed back due to the opto coupler diode going open circuit. In most cases, when the HT rises C720 fails and no other components are damaged. If this is the case, replace C720 and IC705 using the part numbers listed below. Occasionally other components can fail, normally this will be the line output transistor, Q601 (BUH515 - RH-TX0144BMZZ) and IC1801 (TEA5101A - RH-IX1416BMZZ) on the CRT Base PWB. It is important that before the set is switched on after replacing any faulty parts, continuity is checked as follows: 1. 2. 3. 4. From pin 1 of IC705 to the cathode of D725. From pin 2 of IC705 to R724. From pin 4 of IC705 to the base of Q703. From pin 5 of IC705 to the junction of R722 and C717.
It is also advisable to check the components around the feedback opto coupler for failure. To ensure that excessive HT does not cause further problems, make sure that an avalanche diode (D735) is fitted across C720 on the print side of the PWB. The cathode of the diode should be connected to the positive side of C720.
REF NO IC705 C720 D735
DESCRIPTION IC, CNY17F-2 Capacitor, 100!F 200V Diode, avalanche
PART NUMBER RH-FX0110BMZZ RC-EZ0258CEZZ RH-EX0875BMZZ
PRICE CODE AD AH AD
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Sharp Electronics (UK) Limited
Reference JC20062000-2 Revision 4
White Carry out as required Yellow Carry out as required and whenever the unit comes in for service Red Carry out on all units
CTV2000 08 20 TELEVISION TECHNICAL BULLETIN
Month of Issue: September 2000 Classification: White Page 9 of 9
SYMPTOM Field fold over at the bottom of the screen after about fifteen minutes, which gradually gets worse as the set warms up.
CAUSE ACTION
C505 breaking down when warm. Replace C505 using the part number given below.
REF NO C505
DESCRIPTION SMD Capacitor, 100nF
PART NUMBER VCKYTV1HF104Z
PRICE CODE AA
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Sharp Electronics (UK) Limited
Reference JC20062000-3 Revision 2
White Carry out as required Yellow Carry out as required and whenever the unit comes in for service Red Carry out on all units