NEC MultiSync FP1370 Service Manual page 100

CONTINUE
NG
IC571 failure
OK
Check S-correction capacitor
Switching circuit
NG
MQ571, Q572, Q573 failure
OK
Check whether IC592 pin 1 on DEF PWB
and IC531 pin 5 vary by horizontal
size control in OSD menu or not
NG
Digital control circuit or IC592 failure
OK
Check Q561 FBP
See Fig 5.1.2
NG
Q561, D561, D562, C561, H-DY or their ambient circuit failure
OK
Check the distortion correction circuit (see item 5-6)
OK
H OSC/DEF/HV circuit failure (see item 6)
Check the operation of MQ571, Q572, Q573.
Measure the voltage at Q561 Collector.
Normally, this voltage varies from 850 to 1200V by H-SIZE control for user.
Measure the voltage at IC592 pin 1 and IC531 pin 12.
Normally, pin 1 voltage varies from approx. 3.5V to 5V
and pin 5 voltage varies from approx. 0.9V to 5V.
approx.
2.0 usec
Fig 5.1.2
7-12
approx.
850～1200 Vp-p