Whirlpool belt-drive won't spin when it's supposed to and i don't know what to do

Ahhh....Sweet sweet success.

As mentioned above, I suspected triac 105 (Agitate triac) was "latching up" which is a common failure mode of triacs. They turn on when they are supposed to, but won't turn off until power is completely removed. Thus the washer would agitate, but never switch into a drain cycle (even when the controller signalled the triac to turn off. Since the controller board never saw an "empty" signal from the water level switch, it would agitate forever, or at least until I turned the washer off.

I ordered a triac from Mouser Electronics for 32 cents, and it took just a few minutes to unsolder the old one and solder in the new one. It just ran a complete "Gentle" cycle start to finish, which matched the timing diagram exactly.

Gene, thank you for your reassurance and help. Without it I would have spent way too much time on mechanical stuff.

By the way, I couldn't match the part number of the 23-year-old part, so I just bought a way-overrated part in the same TO-92 package style as the orginal Motorola part. I suspect a 1-amp 125 or 150 volt part would have worked, but the 800-volt, 1-amp part was only a few pennies more. I got a ST Microelectronics 511-Z0103NA5AL2.

Larry Marks
Computer electronics engineer for the last 39 years.

Well, it wasn't mechanical. Everything was smooth, even before I added a little grease on the friction points.

So I laid on the floor and watched a gentle wash cycle. This is the most diagnostic, because you can tell when the agitate cycle is "supposed" to end because the motor switches from low to high speed. The agitate solenoid is supposed to release. My first guess was that it was mechanically not releasing, but when I actually watched through the 8-minute wash cycle (electronic timer, no way to speed it up), I saw that the solenoid was not releasing. It still had power when the motor went to high speed, supposedly to pump.

So you were right, Gene. It is the controller board. I have a couple of EE degrees, and have had good luck fixing such things. (I fixed an engine control module (ECM) in my Mitsubishi for $4.00 in parts, saving $500.) So I looked at the board for a few minutes.

My guess is that triac 105 is "latching up". Triac 105 is the agitate triac, connected to the Yellow wire. It turns on but won't turn off. When I power off the entire washer to force a spin cycle, it of course unlatches. A new triac, just ordered, costs 32 cents. I will solder it in and see if that fixes things when it arrives. If not, I haven't lost much.

I needed to order some other parts to fix a heat pump controller board anyway.

Thanks a lot for your encouragement. You were right after all.

Larry Marks

I have it figured out--amazing what a good night's sleep will do.

For some reason, the wig-wag can push the agitator cam towards the front when it's supposed to, but is not retracting it when that's supposed to occur, for a drain cycle. (If I manually force a spin cycle, that's enough to cause the retraction.)

First I will try lubricating the cam and slide areas. If that doesn't do it, I will watch the operation and see if there's too much wear.

Both of the solenoid armatures are really sloppy fits inside their coils. Are they supposed to be that sloppy? Or are they supposed to be a snug fit? I'm thinking that the solenoid armature goes off axis enough that the pin doesn't reach the lower cam slot and doesn't drop.

Larry M

An additional clue: I ran a gentle wash cycle, which is supposed to agitate (low) for eight minutes, then partial drain. Instead it ran agitate (low) for eight minutes, then switched to agitate (high).

Now to figure out what's different between drain and agitate high.