Abnormal Picture - NEC MultiSync FP1350 Service Manual

5. ABNORMAL PICTURE

5-1. Horizontal Size
Check HV voltage
NG
OK
Check 8.5V line
NG
OK
Check the voltage which is supplied to CPU
NG
OK
Check the horizontal frequency mode output (IC571 pins 5~7 10~12) See Fig. 5.1.1
f H 1
f H 2
f H 3
f H 5
f H 6
f H 7
CONTINUE
Measure the voltage at CRT anode.
Normally, the voltage is approx. 27KV.
HV circuit failure (see item 6)
Check the voltage at CNP pin 6 on the VIDEO PWB (PWE-567A).
SW REG. failure (see item 13)
IC801, IC802, IC8G1, IC7A1or their ambient circuit failure
3 3 . 6 k H z 4 1 . 5 k H z
3 0 . 8 k H z
3 6 . 6 k H z
6 5 . 5 k H z
4 9 k H z
5 7 k H z
5 2 . 7 k H z
4 5 . 8 k H z
Fig 5.1.1
7-11
8 2 . 6 k H z 1 1 5 k H z
6 9 . 5 k H z 1 0 1 k H z