Preheat resets power
Suddenly, when I set the printer to preheat, it turns on the heaters, starts to raise the print head and power cycles. The search terms are so general, that I'm having difficulty finding existing documentation.
Okay, a little more testing shows that it power cycles when the bed heater turns on. Can someone point me to the documentation I'm looking for?
Further testing showed that it only power cycled with the textured sheet installed. I had noticed what appears to be exposed copper close to the 50mm mark on the heated bed at the very front of the heated bed months ago - almost immediately after assembly. Recently, a spot of exposed copper has appeared near the 200mm mark at the very front of the heated bed. I covered them with electrical tape and installed the textured sheet, and the problem seems to have been resolved. Now, I've created a terrible bed leveling problem.
Am I going to have to replace the heated bed?
I would plan/expect to replace your heat bed if I were you.
Unless you could find some kind of thin insulator like paint or kapton tape precisely cut and fitted? ensuring a flat build surface is gonna be quite hard if you're adding any material thicker than the insulation on a PCB or overlapping the remaining insulation.
Use a good quality of clear fingernail polish. It is a great electrical insulator. Brush it on thin, one or two coats, and you will be good to go. It will self level. I did this on my MK3S heat bed to fix a nozzle scrape.
Thanks, @Mike Gan!