KX-155 Resetting in flight

NealRomeoGolf

NealRomeoGolf

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Was making my way back on a long cross country tonight from Pittsburgh and after switching to another frequency, all the sudden my KX-155 resets itself to 120.0 on both Comms and 110.0 on both Navs. After some googling, it appears this is what happens when you reset the radio. But the procedure for resetting the radio is to turn it off, hold down the switch button, and turn it back on. So somehow my radio is thinking I'm trying to reset it. Anyone had this happen before?
 
Reset it how? Mine come back on at power up wherever they were before they were turned off.
 
When I hear "resetting" I automatically hear "circuit. breakers"
I wouldn't reset a breaker unless the system was required for safe flight, and even then I would look for an alternative.
 
denverpilot said:
Reset it how? Mine come back on at power up wherever they were before they were turned off.
Click to expand...

In this case, I was flying along talking to Grissom Approach on 121.05. He asked me to switch to his other frequency of 123.85. I dialed that in, hit the swap button and immediately the radio turned both Comms to 120.0 and the Navs went to 110.0. For a second I was confused at what happened, then panicked that I couldn't remember what frequency I was supposed to be on. Thank goodness for electronic AFD's. It happened two more times (one right as I switched to Tower on a short base) before I landed.
 
sounds like the internal backup power has gone bad and the radio lost power for some reason. i think you are heading to the radio shop, bring cash, lots of it!

bob
 
The 155 is broked and needs to partially come from together.
 
Another option you have is to just buy a cheap replacement 155. There are plenty of them out there due to many recent panel upgrades. You might get lucky and score one for a few dollars.
I can ask our local avionics shop if they have a few of these "paperweights" (that's what they call them) sitting on the shelf.
 
KX155 is far from paperweight. They still sell for 500+ for 28v non-gs and 1000-1400 for 14v gs...
 
@NealRomeoGolf : You didn't buy this guy's radios did you? :)

https://www.pilotsofamerica.com/community/threads/kx-155-memory-loss.32737/

Or this guy's?

https://www.beechtalk.com/forums/viewtopic.php?f=21&t=101074

(Requires login)

It sounds like the non-volatile memory has a problem. As far as the radio losing power goes, could be... did it usually die right as the flip-flop was pressed? That could be mechanical (tighten the Allen screw holding it into the tray -- lower center of the front bezel there's a hole if I recall) or the memory could have a problem that's triggering a soft restart of the radio's electronics.

As I recall that board doesn't have much on it, but it had a lot of through-hole stuff in earlier years and vibration may have killed a solder joint or similar. I also think that radio uses an EEPROM for storage and those were rated for long life but in practice, some go bad.

The real pain is finding an avionics shop with someone good at component level troubleshooting. They're becoming hard to find in the brave new world of board swappers.

Just for fun, a few years after we had it uninstalled, I handed our "unrepairable" ADF to a ham radio buddy who likes restoring old stuff. It's been fixed and operating perfectly on his workbench for a year... the repair part was $1.50 but it took him a week on the bench to find it. At current shop rates, its often not financially prudent to do that much troubleshooting anymore, is the real problem.

From what I've read, Honeywell will charge a fortune (if they'll even work on them now) and it'll take them months to send it back.
 
Sounds like I may need to do my main work on Comm2 (another KX-155) and leave Comm1 as my ATIS grabbing machine. Right now upgrading to a Garmin device (430W or something) isn't really in the budget. Honeywell (BendixKing) was running a special where you could send your radio in and they would refurb it with LED displays and check for other issues. $1800 just doesn't sound like a "special" to me.
 
NealRomeoGolf said:
Sounds like I may need to do my main work on Comm2 (another KX-155) and leave Comm1 as my ATIS grabbing machine.
Click to expand...

Swap the radios in their racks. If it is the radio itself with the problem then you can still keep your normal flow of using comm 1 for typical communications.
 
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