User's Manual

P-379 Processor
21
6.0 PROBLEM TROUBLESHOOTING GUIDE
The guide below covers some typical symptoms, possible associated causes and
suggested actions to follow before returning the unit for repair. It is not meant to be all-
inclusive.
Symptom Possible Cause Suggested Action
No output
Weak output
Unit tuned to output channel
different from desired (this
occurs particularly on the units
which have green LED on the
front panel to indicate “T”
channels and channels above
99)
Ensure selected output
channel is desired channel
Unit tuned to input channel in
a different range than desired
Check INPUT SOURCE
SELECT switch for proper
source selection
Input signal is too weak Ensure input signal strength is
within specified range
IF loop cable on rear of unit
loose/disconnected
Check IF loop cable is
securely attached
Unit not plugged in or not
getting power
Check power cord and power
source, fuse
Excessive noise
Spurious signals
Output level above rated
maximum (most often occurs
when changing from high-
number channel to low-
number channel, especially to
the “T” channels)
Measure RF output from rear
panel jack and adjust front
panel OUTPUT LEVEL control
as required
IF level too high (most often
occurs when routing IF
through scrambler or other
external device)
Measure normal IF output
level for applied CW
/unmodulated input carrier and
ensure same level is returned
to unit after external
processing
Input signal too strong or no
input signal at all
Measure input RF level and
pad to within specified input
levels; if signal not present,
change to active channel
Bad/noisy video Aural carrier interfering with
video carrier
Measure Aural Carrier level
and/or adjust AURAL
CARRIER LEVEL control on
front panel
Channels do not change Delay feature active Hold channel change switch in
raised/lowered position for at
least three seconds