Thanks for the direction. I’m guessing something is messed up in the EEPROM. I do have some experience with microcontrollers, etc. Any (reasonable) chance of me digging in to diagnose that?
🙂 Very aware of putting 24 VAC on something that’s not designed for it would create a bad day for the device. I was just highlighting one of the steps I ran to test (using a 24VAC transformer to actuate the solenoid designed for such – completely isolated from the rest of the system – other than the water lines themselves, I suppose. ha!)
As an update, I read several pages in to this forum where you mentioned that anything up to 12vdc would be safe for the frontend circuitry. I used a 12vdc 1amp supply and this was able to open and hold the valve. Using a scope, I watched the capacitor you use for the inrush demand (awesome design, btw) and saw no ~22v charge. I guess this is expected as it thinks it’s an AC controller. So I view this as a temporary workaround.
Happy to tinker/test if you can help. Otherwise, I’ll consider ~8 years a decent service life and order new, etc.
Thanks again.