I've got a MakerFarm Prusa i3 with a Mk1 heatbed, it used to work fine, however recently it is no longer getting up to temperature. I've tried putting the HBP on it's own power supply switched through a relay off the RAMPS board, and that didn't seem to help so I measure the resistance of the board and it was 1.7Ohms, so at 12v it's only going to drawing around 7A (so only 84W)...What could have caused the bed's resistance to increase. I can't seem to find any physical issues, and the solder joints appear to be fine.
Should I just unsolder the wires and replace them just incase!
Thanks in advance.