NEC MultiSync FP1350 - 5-7.Poor Focus

7-16
5-7. Poor Focus
.
NG
OK
NG
NG
NG
Adjust Focus VR on FBT. (F1 and F2)
FBT, focus lead, CRT socket or CRT failure.
Check the dynamic focus voltage at TP-DF.
H. Dynamic focus voltage is approx. 580Vp-p.
V. Dynamic focus voltage is approx. 170Vp-p.
Check the waveform at CN-DSB pin 1. Check the waveform at CN-DSB pin 2.
Check the waveform at IC513 pin 5.
Check the waveform at IC510 pin 10.
IC510 or its ambient circuit failure.
• IC501,R527 or C520 failure.
• Digital control circuit failure. (See item 12)
Check the waveform at CN-DF pin 3. Check the waveform at CN-DF pin 4.
Q951 or its ambient circuit failure. DEF PWB pattern failure.
Check the Q5X1 Emitter voltage and
confirm the voltage approx. -80V.
Q981~Q985, T981 or their ambient
circuit failure.
Q5X1, Q5X2 or their ambient
circuit failure.
V is NG.
H is NG.
Focus is poor all over the screen.
Focus
p
erformance is different at center and other
p
arts of the screen.
OK
NG
NG
OK
OK
OK
OK
OK
NG
• IC501,R501 or C501 failure.
• Digital control circuit failure. (See item 12)
IC513 or its ambient circuit failure.
Q987, T981 or their ambient circuit failure.