Intercom Failure

[istrumit]

Gradually I will get all the gremlins worked out...Here is a new one.

On a trip from 1K1 to home base, KMQY, yesterday, my intercom failed.

While getting ready to depart 1K1, all four headsets let out a loud squeal.

I rebooted the G900X and tried again. My headset 'sort' of worked after that, but was distorted.

Then, in flight about 20 minutes later....loud squeal and my headset failed...dead.


I could trigger the transmitter, but I could not hear anything and Approach could not hear me. I went a good ten minutes hoping Approach would not ask me to do anything while I figured it out.

I had everyone unplug their head phones, and I flew the rest of the trip by using my wife's (co pilot) head set, plugged into the co-pilot jacks, and triggering her mic.

Occasionally it would squeal or threaten to squeal, but it never really flipped out. Seemed to coincide with my son moving around in the back seat.

On the ground at home, I rebooted the G900X several times, and tested the radios with ground.

Pilot side jacks are completely DOA.

The panel was built by Stein and I have an email into Christer...but I don't think this is panel issue.

Any ideas on how I could troubleshoot this ?

[lr172]

I am not an expert here and I'm sure others will add some wisdom. However, if the problems seemed to coincide with movement in the back set, I would probably try to isolate the wiring. If you have a DB style connector, you could remove the pins for all of the headset/mic wires except one and test.

It might be easier to have the intercom bench tested first. Then, if it checks out start troubleshooting your wiring. I guess it depends on your comfort with wiring and electronics.

Good luck and let us know what you find.

Larry

[istrumit]

Originally Posted by lr172

I am not an expert here and I'm sure others will add some wisdom. However, if the problems seemed to coincide with movement in the back set, I would probably try to isolate the wiring. If you have a DB style connector, you could remove the pins for all of the headset/mic wires except one and test.

It might be easier to have the intercom bench tested first. Then, if it checks out start troubleshooting your wiring. I guess it depends on your comfort with wiring and electronics.

Good luck and let us know what you find.

Larry

I got some good advice from Garmin. They think its a ground short in the cabling. So, they advised that I pull the breaker on the audio panel, which should shunt everything around the audio panel and straight to Comm 1 (good to know BTW).

If pilot side works when audio panel is out of the circuit in this configuration, then the audio panel is the issue..

Else, its a wiring issue.

Will check tonight.

[Raymo]

Another easy check with your multi-meter is to check each pin on the intercom connector to see if any go to ground that should not. Sounds like this may be somewhat intermittent, though.

I had just powered up my intercom for the first time for testing and found the pilot side PTT did not work. After an hour or so of troubleshooting, I narrowed it down to a solder splice near the connector. Sure enough, I had nicked a wire while cutting the outer sheathing.

This kind if thing may not manifest itself right away, as mine did.

[istrumit]

Originally Posted by Raymo

Another easy check with your multi-meter is to check each pin on the intercom connector to see if any go to ground that should not. Sounds like this may be somewhat intermittent, though.

I had just powered up my intercom for the first time for testing and found the pilot side PTT did not work. After an hour or so of troubleshooting, I narrowed it down to a solder splice near the connector. Sure enough, I had nicked a wire while cutting the outer sheathing.

This kind if thing may not manifest itself right away, as mine did.

Thats a good idea...I'll bring my DMM with me this evening.

[istrumit]

Originally Posted by istrumit

Thats a good idea...I'll bring my DMM with me this evening.

After bypassing the Intercom, per Garmin, the problem remains.

So, its time to find the shorted wire...which means, taking out the seats and removing the tunnel/console

....ugh.

[BobTurner]

Look first at the connections, at the panel and the jacks. Very good chance that's where the issue is.

[istrumit]

Originally Posted by BobTurner

Look first at the connections, at the panel and the jacks. Very good chance that's where the issue is.

Unfortunately, the jacks are in the center console and are only accessible if I remove the console...which means removing the seats so I can access the console screws from the side...oh well, at least it appears that its not the intercom unit itself.

[rzbill]

The intercom power down test has narrowed your search to the pilot jack wiring and wires from intercom to radio, correct?

[istrumit]

Originally Posted by rzbill

The intercom power down test has narrowed your search to the pilot jack wiring and wires from intercom to radio, correct?

Yes, that is correct.