SHARP SX68KF7
Manual de Servicio

CX68KF5 SX68KF7

TROUBLE SHOOTING TABLE (Continued)
NO PICTURE
Does the snow noise appear Snow noise increase.

TROUBLE SHOOTING TABLE (Continued)
B
No snow noise.

Yes

on the picture tube at max contrast and brightness control?

No

B
Check pins (6) and (7) of IC800.

Does 5V appear at pins (6) and (7) of TU200 (TUNER)?

No

Check IC600, L200, TU200 and etc.

Yes
Does 31V appear at pin (9) of TU200?

Normal
No
Check IC1751, L201 and etc. Noise or signal appear.

Abnormal
Check TU200, SF200 and their related parts.

Yes

Check TU200, TP201 and etc.

Is AV1, AV2 or AV3 input normal?

Yes

Check Q455 and its peripheral circuit.

No

18
18-1

Which does pin (43) of Noise IC400 appear, noise or signal?

Check IC400 and its peripheral circuit.

Signal
Which does pin (39) of Signal IC800 appear, noise or signal? Are waveform at pins (7), (8) and (9) of IC850 normal?

Is IC800 RGB out Normal?

Yes

Noise

No

Yes

No

Check IC400, Q401 and their peripheral circuit.

Check IC800 and its peripheral circuit.

Check the peripheral circuits of screen heater (FBT) and the CRT.

Check IC850 and its peripheral circuit.

18-2