No Raster - NEC N9902 F-1 Service Manual

5. NO RASTER

NO RASTER
YES
CHECK
B+
YES
CHECK
U301 PIN 1, PIN 2
H/V SYNC
YES
CHECK
U701 PIN 31 IS LOW
YES
CHECK
U301 PIN 26, 28
H/V SYNC
YES
CHECK
T302 PIN 3 VOLTAGE
57V AT 31.5KHz, 172V
AT 93.7KHz
YES
CHECK Q315
COLLECTOR ABOUT
1050Vp-p
YES
CHECK G1
VOLTAGE ABOUT
-45~65V
YES
TROUBLE IN
G2 VOLTAGE
NO
NO
NO
NO
U301,Q312,D317,D111,R387,
NO
NO
NO
21
POWER SUPPLY
CHECK
TROUBLE IN
MCU U701
TROUBLE IN
U301
TROUBLE IN
R312, Q307, Q308
OR DEFLECTION YOKE
TROUBLE IN
Q315,Q318,T301,D320,
D321,Q325,Q305,Q306,T302
TROUBLE IN
Q331, Q323, Q329, R394,
D314, T302, C328, U701