Commodore 1940 - Trouble Shooting Hints

TROUBLE SHOOTING HINTS
1. No Character
NO
Check power
supply & Horizontal
circuits
NO
NO
NO
YES
UllillWIIJ
About 4.0Vp-p
Turn the Contrast &
Brightness control
to maximum
No Raster I Refer to
L- ___ ....J Noraster
Check video output
(IC01) circuit or CRT
TROUBLE IN + 8V
AND +15V LINE
YES
YES
10
Trouble in video drive
IC 101
(TA8631N)
About 45Vp-p
UllllJWIIJ
Trouble in video
output Buffer Circuit
(0803, 0813, 0823
0804,0814,0824)