Heated Bed is not reading room temp

One week in and I have no heated bed. It has been working like a champ, but all of a sudden it stopped reading its own temperature. Nothing dramatic happened. I terminated a print that have crapped out after about 25 layers. Then the heat of the bed dropped to zero, I tried to fire it up for another crack at my print. Nothing.

Any ideas?

Thanks

If its reading zero then its not reporting the correct temperature. As opposed to reading ambient temperature.
Check all the wiring to the thermistor.
Take the thermistor wires from the hot end and put them in the bed thermistor connector on the control board. If it reads a sensible number then the board is OK.
Measure the resistance across the bed thermistor wires.
Let us know what you find.
Next step is to remove the bed heater and check the thermistor itself.

All the wires look to me. I double check the board with the thermister wires from the hot head. It read just fine. It must be the thermister on the hot bed its self.

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Thank you

3D Printer:

Prusa i3 V2 DIY kit by RepRapGuru
Microcontroller: Arduino mega 2560 R3 clone
Print area: 8 x 8 borosilicate glass
Bearing: LM8UU linear bearings; 623ZZ bearings
Heated bed: Dual power 12V/24V (Pre setup for 12V)
Extruder: Mk8/9 Direct drive
Power supply: 360W 12V 30A
Stepper motor: 5 NEMA 17 4.8kg/cm
Belt: GT2
Board: RAMPS 1.4
Stepper driver: A4988
Endstop: Electronic end stop circuits w/ LED (3)

Upgrades:
Plywood mounted