J

jtrollin

Well Known Member
I have a PS Engineering 8000B audio panel. It randomly power cycles when the engine is running (can not reproduce when engine is not running).

I have a VPX Pro and have tried different ports for the power with no change.

I have sent in the audio panel and they sent me a repaired one back, no change.

I have inspected the power and ground wires, they are not loose, have proper crimps and shaking them does not cause the issue.

I have a G3i electronic ignition, today when flying on a whim I turned it off and the issue never happened, I turned it on and a few minutes later it power cycled again. Gone to test this more tomorrow.

What could cause the audio panel to shut off? Where else can I look? Sometimes (usually at startup, but once in flight) it will power cycle like 15 - 20 times in a row VERY quickly.

I am at a loss..

thanks for any help....
 
The G3i is creating huge power pulses as it charges/discharges its capacitors.

Power it with a fat wire, and as close as possible to the battery and away from the avionics bus.
You can also use a big MSD capacitor to get rid of the pulses. I've got one I can send you if you want to try it.

Lenny
 
So should I add it in addition to the MSD 8830 Red Noise Capacitor or replace it? And any idea why it only affects my audio panel?
 
Chad had me try different pins. I did that and the problem is still there.

I have not heard back from Thomas yet as the G3i correlation just happened yesterday evening on a test flight after looking at the power and ground wiring to the audio panel.

I might try to put the G3i on a different bank than the audio panel in the VPX config and see if that does anything.

Just such a weird problem to chase.
 
I had my 2 out of 3 grimlins solved PMA8000b

One of them was like yours i got under the pannel and heard klicking of relays inside PMA when it is rebooting and found one of the wires of headset
Was touching ground dont remeber witch one exactly but this problem was solved
Grimlin 2 was Pass filter on Mike line capacitor dead no mike signal was delivered to radio in fail safe or normal op mode. on there website they say this filter never fails. But as you can see this is boooool

Grimlin 3 i am fighting is. During flight intercom squelch getting constant ajustment by there proprietary technology it is increasing sencitivity to the point where mike starting to tripp squelch and you hear the engine noice then it sets squelch higher and starting again to increas sencitivity basically every minute i have tripping of squelch
Not sure yet if i can catch this grimlin without shipping to service

Also i see many resettable fuses inside the pma. One of them could be bad as weel
 
From the IM..... I suspect as the above post noted. Try a temporary wire directly to the master solenoid using a fuse.

When connecting the large lead from the MSD 6a amplifier or Series ?2 module, a good location is the cold (switched side) of the master solenoid. Connecting the power close to the battery will reduce
the chance of instrumentation/radio interference.
The power toggle switch can be also wired
independently with the use of 18-awg wires.
 
So might have fixed it

moved the audio panel to a different Bank from the 3Gi and took it out for a test flight. Problem never occurred, so fingers crossed.. Still weird issue..

John
 
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