[bikestuff]

That's pretty interesting!  It looks like your board had already been modified with a jumper on the back of the board. (first picture).   The board looks very similar to mine, but looks "newer".  I suspect that the board is repairable.  Here is the company that rebuilds them...   You might want to contact them. Flight Systems

Since your board already had that jumper wire (before the event)....and failed anyway, maybe there is something in your compressor that is pulling too many amps.  This is above my pay grade ....maybe one of the real engineer gurus can chime in with an opinion.

There seems to be problem with the link.  Here is another try...Flight Systems

[Chester Stone]

I agree with Bill. I would call Flight Systems and email them the photos you have posted here. They repaired both of my control boards but the burns were not as serious as yours. If they can repair it, I would certainly install the relay system to prevent future burns.

[David and Teresa]

They said my boards were not repairable. Could it be the sections I need to use are OK?

[folivier]

Thinking out loud, and I don't have any experience with this, but what about a mini computer something like a Raspberry Pi?
Correct me if I'm wrong but the control board basically just takes a signal from the thermostat and re-directs that to start up and run the compressor and blower fan. The second compressor turns on when there is a 4 second? difference above temperature set point. So couldn't someone take a mini computer and build a simple logic program to do the same using relays? Or possibly even a simpler processor?
There should be plenty of room to mount it inside a box near the air conditioner. That could solve your problem if it works as I've envisioned it in my cluttered, mangled mind.

[77newell]

Forest suggests something intriguing though I would think a simple programmable controller would be easier to implement. Programmable controllers can have all sorts of inputs and 120VAC output relays are typical.

[folivier]

Just doing a quick web search this popped up for $49 dollars. Add a few relays, could it replace the SCS board? Or even the Dometic boards?http://velocio.net/ace/

[bikestuff]

For the non-programmers a generic HVAC board might be easier.  I found this one Amazon HVAC Board

I am not sure of the current requirements of the relays that we used but we can research it.

The benefit of using a board like this is we could junk the low-tech thermostats and use something a little more modern with Wifi and automatic set-backs, etc.

[Chester Stone]

David, since you have two a/c systems, I suggest you go ahead and install the relays on the unit that is operating. Doing so will give you insight as to how the board is wired to the relays and may give you an idea whether on not he faulty one can be bypassed. Also to the extent that resistors and other components need to be replaced, the operating board should show part numbers. Another thought is to take both boards to someone who is talented working with similar electronics to see if he can repair the burnt one by referencing the good one. Just trying to solve a very difficult problem.

[David and Teresa]

David, since you have two a/c systems, I suggest you go ahead and install the relays on the unit that is operating.  Doing so will give you insight as to how the board is wired to the relays and may give you an idea whether on not he faulty one can be bypassed.  Also to the extent that resistors and other components need to be replaced, the operating board should show part numbers.  Another thought is to take both boards to someone who is talented working with similar electronics to see if he can repair the burnt one by referencing the good one.  Just trying to solve a very difficult problem.

That's what I have been thinking. I would like to find out if some off-the-shelf board could be substituted though. It seems like it should be possible.

[Land Yacht]

I added the air conditioning relays today with the help of a local heat and air guy I know. Bill advised us today and Richard did a couple of days ago when planning - thank you both! Due to the help planning and implementing, we were successful on first attempt, and just in time. One connector was black but still functioning. I am sure it would have failed shortly.

I wish I could contribute to the brainstorming for an alternative board fix but this is NOT my field of expertise. I am very appreciative of those with expertise sharing and helping! I will sleep better tonight knowing this mod is done.