Been off the Forums here for quite a while, 7 months I think, but wanted to share this.
I know many here have experienced reset issues with WPC based Pins. I know there is a pinwiki dealing with this issue as well. My WCS94, late last Fall, began having reset issues. Since it is out in the garage and Winter was approaching, I put the repair on the back burner until last week.
I knew it wasn't the filter Caps on the power/driver PCB as I had changed 5 of them a year earlier. I got out my scope and DMM and monitored the +5VDC output. I noticed it would drop below 4.75 VDC. Actually the +5 VDC would fluctuate from 4.75 to 5.1 VDC. There was no particular pattern or time involved. The 5 VDC could be steady for a while or it could vary. I started suspecting the LM323 +5 VDC Regulator. However I scoped and DMM'd the input to the LM323 and saw my filtered DC input voltage was varying all over the place.
I replaced the BR2 Bridge Rectifier and the reset issue is Gone. The LM323 needs to see a minimum of 7.5 VDC to reliably output a constant +5VDC. Actually, that low limit is pushing it. It should be at least a couple of volts higher to give it some fudge factor.
This reset issue affects a lot of the WPC Pins. My advice, if you get the reset issue, is to get out your DMM and Scope, if you have one, and do some voltage monitoring, versus shotgunning of components.
Another possible reset cause is the Thermistor in the AC line input.
Anyways WCS is running great right now..