For a couple of weeks, the refrigerator has stopped cooling. The fans within the refrigerator/freezer were running when the doors were closed and the condenser fan was running. Compressor was cool.

On the first failure I removed the panels on the rear, vacuumed out all dust, the refrigerator started cooling again. Compressor was sounding like it was working and got warm.

Second failure, I figured that moving things around "fixed" something so I just started tapping things with the hard plastic handle of a screwdriver. Eventually, I heard the compressor motor running again and the unit was cooling. Disconnecting an inline plug near the compressor stopped the fans and compressor. Reconnecting it started the fans up again, but not the compressor. More tapping started it back up.

Third - Fifth failure. I think I narrowed it down to the controller board. Tapping each relay, I eventually heard a click followed by the compressor starting to run properly. I am 90% sure that once the compressor stops (refrig/freezer reaches proper temperature), a relay opens and does not get closed when the controller tells it to. I am also about 75% sure it may be the large non-rectangular relay near the wound coils at the top of this picture:
. The one just below the green tag on the wires.

Tonight I will remove the board and inspect the back of the board for cracked/intermittent solder joints and reflow the solder connections if necessary.

Am I right in guessing that this relay controls the compressor or is it another relay? Is there another possible cause or something else I should check?

I think we bought this refrigerator nearly 12 years ago. Everything else on this unit seems to work fairly well after all these years even with 2 very hungry teenage boys.

Thanks,
Roy

Yes, I kind of figured that out. At least I know that there is a possibility of fixing it and your confirmation lets me know that it is the right thing to check out. What I might also try doing is to jumper the relay closed so that it is continuously cooling.

It's not the best thing, but at least the food won't spoil until I get a replacement motherboard.

Thank you very much for your help.

Well, good news so far.
I pulled the control board and Ohm'ed out the contacts of the compressor relay. The solder joint to the common pole seemed to be intermittent. Under magnification, it looks like heat and age cracked a partially cold solder joint and it was being held together by the layer of conformal coating sprayed on the board.

I scraped off the coating around the joint, wicked off the old solder and reflowed the joint with some 63/37 solder.

After reinstalling the board and applying power, the relay clicked and the compressor started up. I tested the relay by unplugging the inline connector to the fans and compressor, when I plugged the connector back in, the relay kicked the compressor back on.

I'll keep tabs on how this works over the next several days and I will turn the settings down to 7 to make sure it has a chance to cycle off and on.

Thanks for the help and especially for this forum.

Edit: 2 weeks later and the refrigerator is working fine. Makes lots of ice and quickly. Food in both sections are staying very cold even at mid range settings instead of the previous setting of 9 and 9.

Same basic issue. Came home to a warm fridge. Thought the worst. Checked voltage to compressor, got zero. Breathed a small bit of relief it wasn't necessarily the compressor, and started to look to see who could get me a board quickly. Of course this site is the best. Right before clicking order button, pulled the board off. Sure enough, back of the board, one solder joint was clearly burned out. Got out the trusty solder iron and fixed it up. Compressor came on, and fridge is cooling again. Sweet.

Had the same problem myself, and fixed it thanks to this thread. Thought I'd post some pictures if I can.

Here's the relay that switches on and off the compressor: