HP8920A locking up

[bradlington]

HP8920A locking up:

Over a short period following symptoms:
Lost second audio generator on RX
Lost audio from internal speaker
Error code :0040
After 10-20 seconds the menu would lock up and freeze .
Only way to fix was power cycle

Basic cleaning:

Cleaned all cards with brush and compressed air.
Removed all eproms and reseated .


code cleared and "ALL Tests Passed" after power on.

I still have the following issues:

No audio
Second audio generator not working
max deviation seems to max at 1,8 khz

When I move squelch from fully counter clockwise to clockwise squelch triggering - the screen / disply freezes .
When recycling the power all tests passed and can use the unit as long as the I do not trigger squelch- so I leave it fully counter clockwise.
Anyone else have ideas for fix.

Regards

Bradley

[jry]

re-cap the power supply ...at least the low voltage filter section.

The 8920A is in the twenty year old range and the power supplies are starting to go ....often preceded by a bad smell or puffs of smoke on power up

[nukedude]

This happened to several my last employer had. Be sure to replace all of the power supply caps. Initially we only replaced the ones that were noticeably bad. The fix lasted a few power cycles. After all caps in the power supply were replaced, the 8920's work perfectly.

We had the smoke from the power supply on power up, as well as it having trouble switching from TX and RX tests. You would have to press the button a few times, and sometimes power cycle it to get it to switch modes.

They make the Aeroflex 3500A's look bad. The 8920 is still the work horse out there. The new caps made a huge difference. This saved 7 HP8920A's from the scrap heap.