Service manual

CB-34
CB TROUBLESHOOTING
Check audio
power supply.
Is +22VSB
present on pin
10, IC804?
Start
Does DC level
change at pin 14,
IC6000, when
speaker cut-off is
toggled?
Is L/R channel
audio missing at
pins 2, 5, IC804?
Is L/R channel
audio missing at
pins 6, 7,
IC1400?
Is composite
audio missing at
pin 19 of
IC1400?
Is composite
audio present at
pin 1, IC1200 (or
IC1250)?
Replace IC6000.
Replace IC804.
Check IC1400
VCC. If it is
present, replace
IC1400.
Check L/R
channel lines.
5. No Audio
Yes
No
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
Replace IF
processor.
Check Q1290,
1291, 1292, &
1293. Replace
as necessary.