IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM

New IFD440 doesn’t transmit

Printed From: Avidyne
Category: Avidyne General
Forum Name: IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM
Forum Description: Topics on Avidyne's IFD 5 Series and IFD 4 Series Touch Screen GPS/NAV/COM
URL: http://forums.avidyne.com/forum_posts.asp?TID=2354
Printed Date: 06 May 2025 at 2:41am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com

Topic: New IFD440 doesn’t transmit

Posted By: djones584
Subject: New IFD440 doesn’t transmit
Date Posted: 30 Apr 2022 at 10:16pm

Hi folks,

I just purchased an IFD440 to replace the old Garmin 430W in a RV10. I did the usual - take pictures of all the config pages in the 430W and installed the IFD440. Everything worked fine except that the IFD440 will not transmit.

It receives fine, just no transmit. NAV / GPS works fine and it drives the AP on approaches, etc.

Under system status — VHF has a red X on VHF, the other 4 a green OK. When I key the mic, the AUX warning is COM TX Fault.

One thing that was suggested by a friend / great RV guy that has the IFD440 as well was that it was potentially power related.

I verified that I have 13.4 (which is what is on the battery) on P1001, pins 19 & 20 and

P1002 pins 11&12.

I pulled the IFD440 and slide the 430W back into the stack and it still works the comm just fine. Any ideas of things to check on the IFD440?

Thanks,

Doug

Replies:

Posted By: eallevato
Date Posted: 01 May 2022 at 12:08am

Make sure that pins 11/12 of P1002 are fed by a 10 Amp circuit breaker and pins 19/20 of P1001 are fed from a 7.5 Amp circuit breaker.

Gene

-------------
Gene

Posted By: djones584
Date Posted: 11 May 2022 at 9:00am

To post the conclusion...

After contacting tech support and uploading the logs: "Thank you for uploading the logs. Upon reviewing them, we have determined that your unit has an internal fault. The Comm Tx Fault that you are seeing is an internal issue where the transmit line is stuck in the transmit state."

I worked through Rob @ Advanced Flight Systems and Vic Syracuse at Baseleg Aviation who had ordered the unit for my RV10 and Avidyne sent me a replacement IFD440. I installed and went flying :). You hate to have problems with a new unit but I did receive great service as all stood behind the product.

Regards,

Doug