has anyone else got corrosion happening on the 2 small diodes/resistors that are attached to the underneath of the Aluminium bed? I’m getting very erratic temperatures with the thermal runaway tripping and causing the printer to shut down Mid print which I’ve put down to these Diodes.
As long as all of the connections at the terminals are tight, that amount of fluctuation is to be expected - and on the heated bed it doesn't matter as much as it would on the hotend side, so long as non of what you're printing is peeling off the platform.
The likely cause of those dips are from drafts or temp changes in the room, you could build an enclosure around the printer or add insulation on the underside of the bed to help - but I don't think this is particularly necessary.
Hi Lee,
Diodes shouldn't affect temperature control in that way, the way it's been soldered is normal.
Check your connections; at the MOSFET, and at the control board, ensure nothing is loose and that there is good contact at all of the terminals.