Electrical Burning Smell from AC Unit

[zboss]

Well... a big (massive) ant fell out. I guess it was chewing on a wire going into the circuit board.

As you can see the board burned.

[jharding]

wow, never seen damage like that from an ant

[Coolerking]

I have replaced many of those, smx 281c boards, never seen an ant cause a short.
The burnt part on the bottom is the triac for the fan by the way.
I have seen the push on terminals get loose and heat up.

[geoleo]

I have had 2 home AC units shorted out by Geckos!!!

[Coolerking]

The purple wire is the feed from the compressor triac to the overload and then it is sent to the C pin on the compressor, if it is loose on the board it will heat up and burn out.

[Cadence]

Originally Posted by zboss

Well... a big (massive) ant fell out. I guess it was chewing on a wire going into the circuit board.

As you can see the board burned.

You might get lucky. We had a TV do that and it only required paralleling the burnt out section of conductor on the board, worth a try.

[zboss]

Who knows - I do know there is a rampant ant here in florida that likes eating electric sheathing - or it could be the loose wire. It doesn't matter - I ordered a new board. I'm going to have to fix the wire that burned as well.

[zboss]

I just finished up with the repair. I replaced the board and some of the wiring. At least two sets of wires were burned and showed a significant amount of corrosion so I cut the wire down to clean and treated the ends with no-ox-id and sealed with shrink connectors.