Last night I completed one print and then attempted another print several hours later. However, the heating bed failed to raise in temperature and stayed at 21 degrees. After several restarts, I was still running into the same issue. I checked the connections and everything seemed to be in place, I then checked the RAMBo to see if there was a visible issue. I noticed in other posts that people spoke about a “blinking red light”, the red light that I see does not blink and just stays on constantly. I am new to the electrical side of things and was hoping someone could help provide some insight.
This happened on my taz6 recently, so i feel your pain. First, the red led is wired into the mosfet circuit that drives the heater. If the bed is trying to get to temperature it will be solid. (At least mine is).
So it looks like your bed is trying to heat (Mosfet is on), but its not Getting current. Often, this means a break in the current path between the board and the bed due to a shorted connector, a wire that has broken due to repeated flexing, a connector that has become loose, or even possibly a problem with the bed heater. You need to test for continuity between the bed and the board in steps to determine where the break is, and then fix as needed.
I checked the continuity and was unable to find a break between the bed. I replaced the print bed wiring and the bed will still not heat. Could it be the board itself?
Yes. Big three are board (including potential component failures, fuses and possible header shorts), wires between the board and bed, and the bed itself. If you look at the link I posted you will see that my bed header on the board burned out. I had to jumper a wire to get things working again.