NEC MultiSync FP1350 - Page 134

7-22
CONTINUE1 CONTINUE2
OK
NG
Check the horizontal sync pulse (HD) at CN-DSB pin 4 on the DEF
PWB (PWE-568).
NG
OK
Its amplitude is approx.3Vp-p at Q502 gate on the OSC PWB (PWE-567B).
NG
OK
Check the abnormal picture. (see item 5)
Check the horizontal input trigger.
Check the unstable picture. (see item 3-1)
Check the Q502 gate pulse.
• IC501 failure.
• Q504, Q505 or its ambient circuit failure.
• R503, R504, R507, R508 or C509 failure.
• Di
g
ital control circuit failure.
(
see item 12
)
Q501, Q502 or their ambient circuit failure.