User's Manual

Copyright Crescend Technologies 11 Rev B
6. TROUBLESHOOTING
6.1. INTRODUCTION
This section contains a list of potential problems and suggested actions to be taken. If the
suggested corrective action does not eliminate the problem, please contact your Crescend
factory for further instructions.
NOTE: Check your sales order and equipment warranty before attempting to
service or repair the unit. Do not break the seals on equipment under warranty
or the warranty will be null and void. Do not return equipment for warranty or
repair service until proper shipping instructions are received from the factory.
6.2. TROUBLESHOOTING
Refer to Table 6-1 for troubleshooting suggestions. It has been found that in some cases it
may be necessary to power cycle an amplifier (turn DC power off and back on without RF
applied) to clear an alarm.
Table 6-1. Troubleshooting
INDICATOR LED STATUS OUTPUT POWER STATUS POSSIBLE CAUSE SUGGESTED ACTIONS
Unlit No power No voltage at unit 1. Check power supply voltage DC PWR ON
(Green)
On Set power Normal operation 1. No action required
Frequency is out of
range
1. Check frequency
The input power is
below the low end of
the rated input range
1. Check input power
Power supply voltage
is too low
1. Check power supply voltage
at amplifier DC connector
during key-up
On (all other
alarm LEDs
off)
Problem inside
amplifier
1. Send the unit back to factory
LOW
OUTPUT
(Red)
On (together
with HIGH
VSWR alarm
LED)
Less than set power
Output load VSWR is
much above 2.5:1
1. Turn off amplifier (or remove
RF input)
2. Check output connections
and cables for integrity and
tightness
3. Check antenna, combiner,
etc. for proper return loss
HIGH VSWR
(Red)
On Less than set power Output load VSWR is
above 2.5:1
1. Turn off amplifier (or remove
RF input)
2. Check output connections
and cables for integrity and
tightness
3. Check antenna, combiner,
etc. for proper return loss
Fan is not rotating 1. Check if +13 VDC is present
on the FAN feedthrough pin
when rf input present (after
3 sec turn on delay)
2. Check if anything is
physically stopping rotation
3. If fan has failed, replace fan
with same or similar fan
Power supply voltage
is too low causing
insufficient air flow
1. Check power supply voltage
OVER TEMP
(Red)
On Less than set power
Operating
temperature of
amplifier is exceeding
safe level. Note:
When unit cools, LED
turns off and output
returns to rated power
2. Make sure that air access to
front and rear of unit is
unimpeded
3. Verify that air vents are
clear of dust and dirt and
that fan(s) are operating
properly. Replace fan if
necessary
4. Check ambient temperature
(not to exceed spec - see
Table 1-2)