7-28
12. DIGITAL CONTROL CIRCUIT FAILURE
12-1. Digital control error
Check +8.5V line Check the voltage at CN-P pin 6 on the VIDEO PWB(PWE-567A).
NG
Check SW REG (see item 13)
OK
Check +5V line Check the voltage at IC8G1 pin 2 on the VIDEO PWB(PWE-567A).
NG
IC8G1 failure.
OK
Check Reset circuit When +5V is supplied to the circuit, IC801 pin 35 should vary from LOW level
(approx. 0V ) to HIGH level ( approx. 5V ).
NG
IC8G1, C814, IC801 failure
OK
Check the waveform at IC801 pins 41 and 42 2Vpp 10MHz sine wave
NG
X801, IC801 failure
OK
Check Sync signals
Check the pulse 5Vpp at IC801 pin 4 (H sync), IC801 pin 36 (VD), IC801 pin 59
(H polarity) and IC801 pin 58 (V polarity) on the VIDEO PWB (PWE-567A).
NG
Sync interface circuit failure (see item 3)
OK
IC801 failure