Comtech EF Data CPA-050 Installation And Operation Manual page 89

C-Band Solid-State Power Amplifier
Maintenance and Troubleshooting
Symptom
Unit does not turn On
(No display, No front
panel lights, No fans)
Fan(s) do not turn On.
Display not turning On,
Missing text, or
Incorrect backlighting.
Table 7-1. Troubleshooting
Possible Cause
Check power cord
connections.
Faulty wiring to 28V
power supply.
28V power supply fault.
Faulty wiring or bad
connections.
Firmware not properly
seated.
Faulty 28V power supply.
Failed fan or faulty
control circuitry.
Firmware not properly
seated.
Faulty wiring or bad
connections.
Failed display or display
control card.
Circuitry on AS/0200 or
10850 PCB.
7-3
Solution
Ensure power cord is connected.
With input power cord disconnected, check
wiring and connections to 28V power supply.
Reconnect power cord.
Check output of 28 VDC power supply.
Remove and replace 28V power supply.
At power-up, the fans are sequenced on. In
Normal operation, the second set of fans
does not turn on until 3 seconds
(approximately) after the first set of fans.
Check 10850 PCB to ensure the
connections at P4 and P5 are not loose.
Check cable connection at the fans. There
should be 24 VDC (approximately) between
the two pins at the fan.
Check cable wiring if faulty or return to
factory for repair.
Fans are microprocessor controlled and
monitored.
Ensure U11 and U12 on AS/0200 are
properly seated.
Remove and replace AS/0200 PCB if
damaged.
Check the output voltage of the 28V power
supply.
Either via the front panel Monitor menu or
using a voltmeter.
Ensure that 28V is present.
Fan defective.
Replace fan.
Return to factory for repair re replacement.
Ensure U11 and U12 on AS/0200 are
properly seated.
Ensure good cable connections from M&C
cards AS/0200 and 10850 to display card
located behind front panel. Check cable
wiring and if required return cables to
factory.
Return to factory for repair.
Return to factory for repair.
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