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Trouble Shooting

NO Raster & Picture

Check the heater element is lighting.




Check the heater voltage.




Check/Replace Increase the screen voltage
FR459,FR901. by using FBT volume.



Check/Replace
CPT. Retrace line is Screen is black.
visible.


Check the waveform Check FBT & CPT socket
at pin 9(R out) of P501A. & CPT.




Check the waveform Check the waveform
at pin 36,38,40 of IC501. at pin19 of TU101.




Check/Replace Check/Replace Check/Replace Check/Replace
IC501. RGB drive circuit Q102,Q201,IC201. TU101.
& CPT PCB ASSY.




VM doesn't working

Check each voltage at pin 6,8 of P402B.




Check/Replace Check the waveform
R420,J823,R429,R428. at pin9 of P03B.




Check the waveform Check / Replace
at pin34 of IC501. R923,R926 & CPT Assy.




Check / Replace Check / Replace
IC501 VM drive circuit.




- 13 -
Skip & No Channel memorized in Digital

Check the voltage at
pin 13 of P503.


33V
Check / Replace Check the voltage at
D816,R829,ZD803. pin 2 of TU101.


High
Low
Check the voltage at
Check the voltage at
pin 3,1,9 of P904B.
pin 16 of IC01.

Normal NG
Check / Replace Check / Replace
Power line of
TU901,IC909,IC910. Digital board & IC111.




2.5V~ 0.5V~2.5V
Check / Replace Check / Replace
Q105,Q104,IC01. TU101.




Skip & No Channel memorized in Analog

Check the voltage at
pin 9 of TU101.


NG Normal
Check / Replace Check the voltage at
ZD802,FR829. pin 13,6,7 of TUNER.


Normal
NG
Check the waveform at
Check / Replace
video-out of TUNER. 5V power supply line
of TU101.

NG Normal
Check / Replace Check / Replace
Power line of
TU101. Digital board & IC111.



NG Normal

Check / Replace Check / Replace
IC02. IC07,08.




- 14 -
NO TELETEXT

Check the waveform
at pin 12 of IC01.




Check / Replace Check the waveform
IC01. at pin33 of IC201.




Check the waveform Check / Replace
at pin 19 of TU101. Q202.




Check / Replace Check / Replace
Q102,IC201. TU101.




NO Sound

Check the voltage at
pin 10 of IC651.


0V 32V
Check / Replace Check the waveform at
FR852,D814,R863,L654. pin 24,25 of IC601.


NG
Normal
Check the voltage at
pin33,46,16 of IC601. Check the waveform at
pin 7,11 of IC651.

Normal NG

Check the waveform at Check / Replace
Power line of IC601
pin 47 of IC601. (ZD601,R601,L603...)



Normal NG Normal NG
Check / Replace Check / Replace Check / Replace Check / Replace
IC601. TU101. SPK. IC651.




- 15 -
Digital Back-end Board Reference

No
Is the power normal? Check : P106 (3.3V,5V,9V)

Yes


No
Check the operation of oscillator Check : X101 (13.5Mhz)


Yes


No
Check the operation of Reset when Check the Reset circuit:
Power On See Reference A

Yes


No
Check the serial communication pins Check :IC101 pins (105,106,111,112)
between u-com and CPU

Yes


No
Is the I C normal? Check IC Circuit : See Reference B


Yes


End




- 16 -
Reference A

No
Check the Reset IC(Pin 2of Q103) Check Q103


Yes

No
Check IC108 (pin 10, pin 12) Check IC108



Yes


End




Reference B

Check the signals of IC101 No
Check IC101, IC111
:Pin 147,148 (SCL1,SDA1)


Yes


No
Check the signals of IC101 Check IC101, IC301
:Pin 149,150 (SCL0,SDA0)


Yes


End




- 17 -
Digital Front-End Board Reference

No
Check at pin5,6,11,35 of TU901 Check at pin 1,5,9 of P904B

Yes


No
Check at pin 86,87,of IC909 Check /Replace IC 902, TU901


Yes


No
Check at pin 2,4,6,8,11,13,15,17of IC905 Check / Replace IC909
Check at pin 2,4,6,11,13 of IC906

Yes
No
Check at pin Check /Replace R917,R918,R919
1,2,3,4,5,6,9,10,11,12,13 of P905B

Yes


No
Is the I C normal? Check IC


Yes


See the Digital Back-end Board
Reference




- 18 -