Service manual

CB-33
Flowcharts
4. No Video
Start
Is raster present
on the screen?
Is 1.07 kVp-p
signal present on
collector of
HOT?
Is regulated B+
present at pin 3
of TX3204?
Check power
supply.
Check TX3204
for high voltage.
Check HOT and
H-drive circuit.
Is there luma at
pin 4, IC2200?
Is luma missing
at pin 34,
IC2900?
Is RGB output
present at pins
22 - 24, IC2200?
Replace IC2200.
Is RGB present
at pins 1, 2, 3,
connector 5C2?
Check Q2205,
2206, 2207.
Is the SETUP
jumper open?
Is +235 VDC
present across
C5100?
Check TX3204.
Check G2
adjustment.
Yes
No
Yes Yes
Yes
Yes
Yes
Yes
Yes
No No
No
No
No
No
No
Remove setup
jumper.
Is composite
video missing at
pin 36, IC2900?
Check Q2901
and +9VSW
source.
No
Yes
No
Check DL2400
or IC2400 and
comb-filter
circuitry.
Is there video IF
present at pin
50, IC2900?
Yes
Check video IF
line, Q1200, pin
21, IC1200
No
Yes
Replace IC2900.