Auto Adjust Circuit Failure - NEC MultiSync FP1350 Service Manual

18. AUTO ADJUST CIRCUIT FAILURE

Set signal all white characters, and perform AUTO ADJUST on OSD control.
When check the following contents, perform AUTO ADJUST at the each time.
Check +5.0V and +3.3V
NG
+5.0V line, IC8M2 or IC8G2 failure on the VIDEO PWB.
OK
Check R.G.B video input signals
NG
Q8M1R, Q8M1G and Q8M1B failure separately
or VIDEO CIRCUIT FAILURE. (See item 2)
OK
Check AFC_TTL input signal
NG
CNASD pin 4 or AFC_TTL line failure.
OK
Check V.PUMP input signal
NG
CNASD pin8 or V_PUMP line or its ambient circuit failure.
OK
Re-adjust Auto Adjust adjustment (Set again AUTO ADJUST L and AUTO ADJUST H)
NG
Failure IC8M1or it's ambient circuit failure.
OK
The video signal was not possible for working correctly of Auto Adjust function.
Make sure that the voltage of C8M7 is approx. +5.0V and C8MF is
approx.+3.3V.
Check the waveform at IC8M1 pin 27,pin 28 and pin 29.
(Approx. +3.2Vp-p)
Check the waveform at IC8M1 pin 14.
(Approx.+5.0Vp-p)
Check the waveform at IC8M1 pin 13.
(Approx. +5.0Vp-p)
7-36
V. frequency
H. frequency
V. frequency