Hello. I have a heavily upgraded RepRap 2020 i3 that was printing well until last night. Part of my heated bed stopped heating, after nearly a year of successful use. Pins 2 and 3 are soldered together for a 12v configuration. Initially, I replaced the thermistor with a brand new one after the bed failed to reach temperature several times--Then I felt the bed to find only the half furthest from the solder pads was heating. I checked continuity in several spots, poking underneath the solder mask with the probes. Everything connected to positive and negative except a small loop along the middle of the board. It almost looks like there are two loops on either side of the thermistor that are not connected by design, however my eyes may have overlooked something. Trying to bridge one of these loops to a connected trace by scraping off the solder mask and soldering a jumper did not restore heating to the other half of the board, so that seems to be a dead end. There is no visible damage to the board besides my attempts to debug the issue--no burns. Has anyone else had this happen? Aside from replacement, how did you fix it?
