Red X's in freq boxes - No Comm with VHF

Hello,

I have had an issue (see attached photo) happening for quite a few months where I would get this error immediately after start-up on the IFD540 in my RV-10. Until last week, the issue would go away in about 30-60 seconds and didn't happen on subsequent engine starts on the same day. When the red X's went away, the frequencies would get reset to 118.2/127.8 and the volume got reset to zero. Over the past couple of weeks, the issue started happening multiple times on each engine start (still only prior to run-up). Then, last Wednesday, the issue happened when I started the unit and it never went away.

I had opened a ticket with Avidyne when the issue started happening many months ago and they had suggested it might be an issue with power to the unit. If the power is ok, they mentioned that it's likely an issue with the unit itself and it would need to be sent in for repair. 

Since it was more of a nuisance for the past few months, I didn't do too much about it. Now with the COM/VLOC not working at all (the GPS part is working fine), it has become a critical issue. Based on a conversation with Avidyne Support last week, I had a local avionics tech do some troubleshooting and it looks like the power and ground to the unit (pins 11/12 and 21/22 on connector P1002) are fine.

There is a shop recommended by Avidyne called Direct Avionics in Novato (about 30 min flight from my home base of KRHV) who said they can bench test the unit for $175 to confirm if the issue is with the unit (or with the airplane wiring).

I am going to call Avidyne but I wanted to get some opinions from this community on a few items:

-my troubleshooting so far seems to strongly indicate that the issue is with the unit itself. I am trying to figure out if it makes sense to spend the $175 plus gas and time to get it bench tested by the Avidyne shop to confirm it or if I should just bite the bullet send it to Avidyne for repair?

-Has anyone else had the same/similar issue and what was the resolution?

-Does anyone know if there is any Avidyne shop closer to the San Jose/South Bay area that can bench test the unit?

Thanks,

Vas

Thanks for the pointer to LAC Avionics. I tried calling the number for them but it gets disconnected right away. I tried sending them an email but it bounced. If you have another ways to contact them, please do let me know.

I did get a pointer from Avidyne to a dealer called NorCal Avionics in Watsonville so i have left them a message.

The first is a 10 Amp c/b dedicated to the COMM portion of the IFD.

The second c/b should be a 5 Amp for the GPS/Nav portion.

Some folks wire in only one c/b for both.

Gene

Gene

Pins 77 and 78 on P1001 are NOT power, those pins are ground.

Pin 44 of P1006 is only used IF an instrument requires the VOR/LOC and Glideslopte Superflags.

In all of the GA installs that I have done, I have never used pin 44 of P1006.

Since your RV is a 12 Volt system, here is a summary of what you should have:

Pins 19 and 20:  12 Volt power coming in from a 7.5 Amp circuit breaker to provide power to the GPS and NAV circuitry. The main wire should be an 18 AWG wire that gets split into two 22 AWG wires to the actual pins.

Pins 77 and 78:  Airframe ground, or the negative side of the battery. The main wire should be an 18 AWG wire that gets split into two 22 AWG wires to the actual pins.

Pins 11 and 12:  12 Volt power coming in from a 10 Amp circuit breaker to provide power to the COMM circuitry. The main wire should be an 18 AWG wire that gets split into two 20 AWG wires to the actual pins.

Pins 21 and 22: Airframe ground, or the negative side of the battery. The main wire should be an 18 AWG wire that gets split into two 20 AWG wires to the actual pins.

That is it.  

Gene

The next step is for the unit to be bench tested on Saturday - that should provide a good path forward.