My guess is that -- not being able to find a capacitor -- that it's motor related. I'll try take some voltage readings and report back. The circuit is shared with the clothes dryer, but with both running, I still get a reading of 123 VAC.
To add some more detail about the problem, it started as intermittent but is becoming more regular, and from what I can tell, it's not always happening between the same cycles. Sometimes it happens right away (between fill and wash) and other times it happens later on (after the wash cycle but before the rinse?).
Here's a link to the service manual
-- found it surfing around the 'net. Page 37 (3-19) talks about adding a capacitor kit. Also, the schematic from behind the control panel shows a capacitor but notes, "CAP. EXPORT MODELS ONLY." The LOW VOLTAGE description, also on page 37, describes the problem I'm experiencing very accurately: "the washer motor will hum and fail to start spinning. If a motor remains to long in the start winding, it will overhead and trip on the overload protector."
Which wires to I test for voltage? Page 92 has the schematic.
If I had to guess, I'd put the black lead on black/brown/orange and the red lead on red/white/yellow. The overload protector looks to be connected through the yellow wire. Do I want to test when it's buzzing/humming, or during regular operation?
Also, this might be thinking ahead a bit, but I think I'm going to add a start capacitor kit, part # 206103
If that doesn't do the trick, the next step might be to replace the motor. Does this sound like a good plan?!