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Circuits to be checked:
• A/V circuit.
• Tuner.
• PIF.
• Peripheral circuit of Bus Line.
Snow noise increase.
Yes
No
Does 9V appear at pin (6) of
TU201 (TUNER).
Yes
Does 33V appear at pin (9) of
No
TU201.
Yes
Does 12V appear at collector of
No
Q201.
Does 5V appear at pin (7) of
No
TU201.
Yes
Check TU201, IC201 etc.
NO PICTURE
Does the snow noise appear
Yes
on the picture tube at max
No
C
contrast and brishtness
control?
Check IC601, TU201, IC201
etc and 9V-2 line.
Check IC203, TU201, L200
Check 12V line IC602 etc.
Check L201,IC606 etc.
Circuits to be checked:
C
• PIF circuit.
• A/V circuit.
• Video output.
• Peripheral circuit of Bus Line.
No snow noise.
Check pin (21) of IC201.
Normal
Noise or signal
appear.
Check Q205, Q215, Q212,
Is AV1, AV2 or AV3
Yes
input normal?
Q213, Q214 and their
peripheral circuit.
No
Check (36) of IC451
No
Check IC451 its peripheral
NOISE or signal
circuit.
appear?
Yes
Check pin (2) of
Yes
Check IC801 RGB
IC802 noise or signal
out Normal?
appear?
No
Check IC802 its
Check IC801, their
peripheral circuit.
peripheral circuits.
Abnormal
Check PIF circuits
and its related parts.
Yes
Are collector waveforms of
Q850, Q851, Q852 normal?
No
Yes
No
Check the
Check Q850,
peripheral circuits
Q851, Q852 and
of screen heater
their peripheral
(FBT) and the CRT.
circuits.
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