Troubleshooting
Symptom
Cause
Possible Solution
PA will not power up
No 12V power to the PA
Check for front panel fuse.
Check for 12V power to PA
PA not turned on
Monitors will not power up
No 12-24V power to
monitors
No 12V trigger voltage from
PA to monitor
Check monitor 5-Amp fuse
Check for 12V to 24V power at
monitor pigtail
Check that PA is set to VIDEO
mode
Check that PA has 12V power
Video screens have
interference
Poor connections
Bad VHS tape
Dirty heads on VCP
Check crimp connections at monitor
Try new VHS tape
Clean VCP heads
No audio from speakers
Speakers not connected
Volume on PA turned down
Measure resistance between gray
and gray/black wires (should be
between 2-16
Ω
)
Measure resistance between green
and green/black wires (should be
between 2-16
Ω
)
Turn volume control up and check
audio from VCP to PA and radio to
PA
VCP will not power up
No 12V power to VCP
Check VCP 3-amp fuse
Check for 12V at VCP power
connector
No audio when MIC is
keyed (other sources OK)
MIC volume control turned
down
MIC defective
PA defective
Turn MIC volume up
Adjust MIC GAIN controls up
(located behind recessed holes on
front panel of PA)
Adjust PA master volume up
Replace MIC
Replace PA
VCP audio has alternator
whine or hum
Ground loop between PA
and VCP
Install NF-20 isolation transformer
on audio output of VCP
Radio has alternator whine
or hum
Power source “dirty”
PA has poor ground
connection
Install NF-12 noise filter on power
leads of PA
Ensure that PA is securely grounded
to metal frame of chassis, free from
paint, oil, dirt, etc.
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