My refrigerator died. It was Friday evening when I took notice, and transferred half the contents to coolers with ice, ate as much as wouldn't keep without freezing, and tossed a lot of the rest.
Tracked down the symptoms, and it's undoubtedly the motor-start PTC resistor unit that emitted its magic smoke. Pulling things apart was amusing (cramped kitchen, with a new island in the midfloor, consisting of coolers).
So, there wasn't any circuit diagram on the back panel, but plenty of internet mumblings and charts (and videos) on the issue. The covers came off and revealed a boxy thing that takes electricity in (two terminals) and sits on two prongs that emerge from the compressor motor.
It's a 'motor protector', 'motor starter', 'thermal relay', 'overload kit', and half a dozen other names also are sometimes applied. The refrigerator manufacturer has discontinued (and/or is just out of) this part, but a different manufacturer DOES still have their 'kit' that the local store can get me, probably with a day's delay. Klixon made this unit, not the refrigerator manufacturer, and has gone through three part-number-revision changes (from 8EA40x to 8EA4Bx to 8EA14Cx...). It took an hour on the internet to find enough info to confidently get a part number that isn't unobtainium.
So, here's the greater issue: my local supplier is an authorized repair center for the refrigerator's manufacturer, so they can only ever recommend the certified replacement part or kit. How many people throw away a refrigerator when a socketed PTC resistor fails? This is a positive-temperature-coefficient "switching" component, which kinda cooks itself as part of normal operation, so they fail quite often.