Heated Bed Suddenly Not Working.

[BLKKROW]

same power supply for both?
fuse blown?

have you checked with a volt meter to check that the power is switching on and off the the SSR, and that the gate on the SSR is functioning? and also, that the PS is supplying 12V then continuity along the lines to see if the wiring has burned up somewhere.

among those checks you should diagnose that its either the board the PS the SSR or the wires themselves.

How would you check the SSR? The voltage difference on the input is 12v but the difference on the out is 0. I am not the best with electronics and want to make sure I am measuring it correctly.