GMA 240 died
 

Folks/brain trust,

I have a Garmin GMA 240 in my panel, not flying yet.

Last weekend I had everything powered up, (everything has been working fine together) and suddenly, without touching a thing, there was a small click from my audio panel and it went dark. Dead, nothing, nada. Checked the panel fuse and insured I have power to the pins. Problem is definetly internal.

So I had 2 headsets plugged into jacks that were wired to a disconnect switch for using monural headsets, which these were. Thought I had the disconnects switched to the "Mono" mode, but i guess I don't know for sure.

The manual says this can cause the "internal power supply fuse" to trip.

Does anyone know anything about this fuse? Can I replace it myself? Is there some other "reset" method I haven't spotted?

Hate to send it in and spend money. :(

Thanks in advance for your help.

Hello Jesse,

Call the number below and you will reach the experimental customer service group. They will take care of you and get your audio going again.

Thanks,
Steve

Yep. The 240 IMHO has a design defect, if it is wired for stereo and you plug in a mono headset it can blow the internal fuses. This is poor design, modern electronics are "short circuit proof". Other brands don't have this problem, nor does my home-built audio panel.

I won't be surprised if Garmin tells you that if you open it up you will void the warrantee. Only you can decide what to do.

GMA 240 cheap fix
 

Jesse,
Good news for you on this topic. Today my GMA 240 died for the second time. This time it was after an inadvertant switching of the stereo/mono switch on our headsets. It still worked in the fail-safe mode which let me transmit and receive on the primary comm radio even though there was no ICS and the entire unit wouldn't power up. After paying $250 to get this internal fuse fixed the first time my Dad and I decided to seek some help at the local Radio Shack before paying that kind of money again. The "Radio Shack guy" spotted the 1 amp fuse right off the bat. He tested it and it had failed. So he wired in a replaceable 1 amp fuse (pictured below) should this ever happen again. We powered it up and it worked like a charm. It cost us about $6.

Another option now that everyone knows where this fuse is located would be to replace it with the original fuse specification:

Click for link to where to buy and specs:


A person crafty in the art of reading specs most likely could find a self reseting poly fuse that would also work in this application.

Obviously any of this will void the warranty so do this at your own risk.

Wow
 

Thanks guys for the information. Hadn't called or sent the unit in yet so I think i'll head in the fuse replacement direction myself! I have a hard time paying $250 to fix a fuse in an $800 audio board. I'll let ya'all know.

Success!
 

Thanks to ApacheJoe for the fix you posted!

I tested the same fuse, found it blown and used the same repair you did.

I did indeed find that both of my mono/stereo headset switches were in the stereo position and I had mono headsets plugged in. Bad flaw in this piece of equipment.

I used an inline fuse holder I had on hand. I reduced the wiring size so I would not have the mass of the large wire to heat up when soldering to the on board fuse. Certainly don't want to put any more heat than necessary on the circuit board.

I also stuck a small piece of brillow pad in there to keep the fuse holder from bouncing around. The brillow pad will also allow air to move so the components on the circuit board can breath.

In the end, I know that I can simply remove the unit and replace the fuse easily in case I forget a switch position.........This just aint right.




Had to use a fine point on the soldering iron and used as little heat as possible. First tin the wire, second tin the fuse then join. Get the heat off.



Happy camper!



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340 too?
 

I was going to pick up a 240, but after reading the issues with it, I'll probably look at something else.

Does the 340 have the same issue?

Cheers,

Don

I had a PS Engineering PMA 8000B audio panel. An excellent panel, and no problem with mono/stereo.

PS Engineering AUdio Panels
 

Don, none of our audio panels have this problem. This is something we solved in 1992.

May I suggest the PMA5000EX?

Mark Scheuer
PS Engineering, Inc.