Focus Poor - NEC MultiSync V920 Service Manual

8. FOCUS POOR

FOCUS POOR
YES
CHECK
T302 14PIN H-DYNAMIC
PARABOLA WAVEFORM 550Vpp,
V-DYNAMIC PARABOLA
WAVEFORM 180Vpp
NO
CHECK
T303 H AND V PARABOLA
WAVEFORM
NO
CHECK
C323 H-PARABOLA
WAVEFORM 29Vpp
NO
CHECK
Q303, Q304 EMITTER
H-PARABOLA
32-Vpp
YES
CHECK
Q301, Q317 COLLECT
H-PARABOLA
5-Vpp
YES
GO TO
FACTORY MODE,
CHOICE H-FOCUS ICON, ADJUST
TO 80~100%, CHECK U301
10PIN FOCUS 3.8Vpp
NO
TROUBLE IN U301
ADJUST
T302 STATIC FOCUS VR AND
YES
DYNAMIC FOCUS VR
NO
V-PARABOLA
YES
NO
NO
25
NO
TROUBLE IN
T303, Q305, R360, R32H,
R331, R339, C322, C324,
C320
TROUBLE IN T303
TROUBLE IN
Q302, Q303, Q304, Q338
TROUBLE IN
Q301, Q307
1. CHECK STATIC FOCUS AND
DYNAMIC FOCUS VR LINE TO
CRT SOCKET
2. CRT SOCKET OR CRT POOR