My heated bed stopped working... (3 replies)

Hi everyone, I've tried searching but am yet to come across anything to solve the issue I'm having (not that I haven't tried all the solutions anyway lol)

I've got a 12V power supply going to a RAMPS 1.4. I had a heated bed hooked up (Mk2) and it worked perfectly for quite a while. Woke up today, tried to preheat it and at about 60 degrees the LED on the pcb turned off and it's never turned back on :(.

Took it off, re-soldered all the wires, checked for continuity. I get 12.6V at D8 on my ramps, 12.6V from the leads when not plugged to the board, and 0.02V when I plug it in. The board is showing a resistance of 2OHMs unplugged and 3.5ish when plugged in. The LED still doesn't turn on and the board is not heating up.

I have no idea how MOSFETs work and only found out what they do today. They seem to deal more with voltage, and I'm getting 12.6V from the wires going to the heated bed (when they aren't attached to the bed). There's definitely 12.6V going into D8 terminal at all times (plugged and unplugged from heated bed).

Is it possibly that when the heated bed tries to draw current through the circuit the FET is failing, or something like that?

It's had me running in circles all day, hopefully the brain bank here can point me in the right direction.

Thanks.