Commodore 1940 - Page 15

3. Horizontal
Output
Circuit
Trouble
in
IC401
Trouble
in
Horl:t
outPllt
citGuit·
.
(NoRast~)
NO
YES
YES
YES
NO
YES
12
Trouble
in
power
supply
circuit
or
0504
collector
short
to
emitter
Trouble
in
FBT
Trouble
in
0503,
T501
If
the
holddown
circuit
stops
the
horizontal
oscillator
during
the
check,
turn
off
the
power
then
turn
on
again
about
10
seconds
later
Check
R531,R556
R555
etc.
Check
15V,
24V
line
and
R402
Trouble
in
IC401
High
voltage
circuit
or
shutdown
circuit