Unstable Picture; 3-1.Horizontal - NEC MultiSync FP1370 Service Manual

3. UNSTABLE PICTURE

3-1.Horizontal

Check H sync
NG
OK
OK
OK
･ H OSC/DEF/HV circuit failure (see item 6).
･ Digital control circuit failure (see item 12).
Measure at CN-AF 5 pin (HD) on the VIDEO PWB (PWE-567A)
Check the input H sync
NG
Signal cable failure
Check the output pulse
NG
Q7Y1, Q7Y2, Q7Y5, Q7Y6, Q734, Q735, IC731 and their ambient
circuit failure on the VIDEO PWB (PEW-567A).
IC7A1 and their ambient circuit failure on the VIDEO PWB (PWE-567A).
Check the sync pulse at Mini D-SUB 13pin on the VIDEO
PWB (PWE-567A).
Check the pulse (HD) at IC731 22 pin on the VIDEO PWB
(PWE-567A).
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