NEC MultiSync FP1350 - Page 124

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