Osc / Def Circuit Failure - NEC MultiSync FP1350 Service Manual

7. V OSC / DEF CIRCUIT FAILURE
Check +15V/-15V line.
NG
• CN-K wire failure.
• Check SW REG. (see item 13)
OK
Check the sawtooth wave at IC421 pin 8 on the DEF PWB (PWE-568).
NG
Check the sawtooth wave at CN-DSB pin 11 on the DEF PWB (PWE-568).
NG
Check the vertical input trigger.
OK
Check the sawtooth wave at IC511 pin 12.
OK
• IC501 failure.
• Digital control circuit failure (see item 12)
OK
• IC401 or its ambient circuit failure .
• V DY failure.
Measure the voltage at CN-K pins K2 and K4 on the DEF PWB (PWE-568) Pin
K2 voltage is approx. 14.5V. Pin K4 voltage is approx. -15.6V.
OK
IC421 or its ambient circuit failure.
NG
Check the unstable picture (see item 3-2)
NG
IC511 or its ambient circuit failure.
Check sync pulse (VD) at CN-DSB pin 6 on the DEF
PWB (PWE-568)
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