Final update - replacing the atmega did fix the problem and I'm back up and running :smilekettle:
Thanks very much, Bryan, for the help and advice. Thanks also, Dave, for saving me a facepalm moment when I got my soldering iron out!
Quick update: Pins 2 and 3 are connected to RX and TX on the Pi Connector and not to 3.3V or GND, so I'll replace the atmega and report back. Thanks again.
Hi all,
I built a HeaterMeter v4.0 a couple of years ago (great project, BTW - many thanks to Bryan and all involved). Everything worked nicely until last week when I had the unit powered up but out of its case and then managed to drag one of the braided probe cables over the assembly; it...