GTX 345 installed, KFC 150 fried

[thomas1142]

Just had a GTX 345 installed, turned the Avionics Master on and smoke started coming out of the panel. Turned out the KFC 150 got fried. I know that the two are not necessarily connected and stuff happens, but what would make the KFC 150 go up in smoke? The avionics shop also installed a GMA 340 and connected all the necessary wiring of a new ELT. All tested good when they finished. It was about three weeks after when I stared the plane that my issue happened.

[Yetti]

Ah the standard.  Hey I saw an IT person on the floor last week and now my computer does not work.  Surly it was that IT guy that broke it.   I would look for reasons the magic smoke can come out of the KFC not the prior install.   I think Caps are one of reasons for releasing magic smoke on old electronics.  Rubbing wires and such might be next.

Edited August 25, 2018 by Yetti

[jackn]

The KFC use the flat slide in connectors. Back in the day just about everything used that type of contact system, but not seating the circuit board properly caused lots of problems. Most electronics today use pin type connectors. 

Not saying that’s what happened, but I’ve seen it before. 

[Cruiser]

I am sure you have seen pictures of the wiring behind a panel. Installing anything is bound to move most of those wires.

It may or may not be related. If the shop actually had all the avionics on and operating (as they should have to complete the install) then I would suggest it was properly wired. 

Look for exposed or damaged wires/connections. (still could have been done by the shop)

Or it was just the A/Ps time. (RIP)

[carusoam]

Somebody around here posted pics of their failed BK AP...

The failure, interestingly,  was the largish capacitors that decided to physically move...

See if we can find that thread... it had some nice pics...

See if @flyboy0681 has some insight...

https://mooneyspace.com/search/?q=Autopilot capacitor&sortby=relevancy&search_and_or=and

Best regards,

-a-

[81X]

If you can’t repair it, I’ll have a KFC150 for sale in a couple of months.  

With that said, my avionics guy said it best- it appears that Mooney built the entire airplane around that autopilot controller!  The wiring for those is intricate and can certainly get chafed, shorted , or pulled out of the harness where it’s super easy for that wire to ground out. 

[thomas1142]

46 minutes ago, 81X said:

If you can’t repair it, I’ll have a KFC150 for sale in a couple of months.  

With that said, my avionics guy said it best- it appears that Mooney built the entire airplane around that autopilot controller!  The wiring for those is intricate and can certainly get chafed, shorted , or pulled out of the harness where it’s super easy for that wire to ground out. 

Ill definitely keep it in mind, thanks.