I just worked on 3 I had here at the house, the compressors were not running on all three.

I started with a switch that plugs right into the compressor, It's a Start Relay & Capacitor.
Wiring just plugs into it, all three frig's I had used the same one.

Cost less that 10 bucks and they are really universal, one size fits all damn near. I bought 2 on Amazon.
Figured on a gamble it'd be worth it.
It was this part right here

Well that got the Whirlpool frig running but not the other two.

Next was a Frigidaire, It just wasn't getting a start signal. If it had been I'd have heard the new relay click, so I dug a little future and came up with a control board that was under the frig. I got it pulled out, again just plugs and a couple screws and I had it in my hand.

It was shorted, big black burnt spot right in the middle of the board.
Ran the numbers on it through Google and found it on Amazon as well.
It was around a hundred a bucks on Amazon but I found one on EBay for 33 bucks so I ordered it.

These parts orders come in fast, a couple days wait and they are in the mailbox.

[Linked Image from i.ebayimg.com]

Buy for 32.99 on EBay at this link.

That did it, The Frigidaire was running like a top!

The third frig seemed to have a compressor issue.
It appears to have run low on coolant and possibly burned up the motor that is sealed inside the compressor tank, it just hums when the start relay snaps closed.

It'd cost me better than a hundred to get a new compressor and then I'd have to have someone charge it with coolant so I quit there.

2 outta 3 ain't bad for $50 bucks and a couple hours of my inexperience time....I did have to view a handful of YouTube videos....

All three frig's are under 5 years old and of similar size. Just didn't want to toss them and buy new, I have a couple houses going on the market and wanted working appliances is them.

The world seems geared to getting us to toss things out and buy new, a good frig not long ago was under a grand, today it's doubled or more....