@klizana I didn't find any specs for the #Jobo so I actually just opened it up and back-engineered myself (the circuit is not that complicated if you've ever looked at electronics before). The key was the happenstance knowledge that diode rectifiers aren't meant to last forever, so this alerted me to that component. The voltmeter was indeed all over the place when looking at its connections.
I'm sure there are lots of #CPE2plus and similar out there just tossed in the bin because of this issue.
