Prusa I pro b. Tryna print with ABS for the first time. Bed won’t heat past 67. Any suggestions?
A sheet of cardboard to insulate under the heated bed will get you maybe 10c. Beyond that, a bigger power supply. Beyond that a new heated bed and a relay.
Do you have another thermistor to replace with the one under the heated bed? Could be that one installed is damaged from too much heat. Also check the wiring connections.
If you have a multimeter, measure the PSU voltage when the bed is on. Just to make sure your PSU isn’t “sagging” from being too much demand for the supply to take. But the bed might simply not be powerful enough.
the clone mk2 beds rarely get past 70 … also u need a thermometer to verify the temperature. sometime 70 is actually 90 or 40 .
Not sure if this would help, but try plotting bed T vs time as it warms up. If you see an asymptotic approach to about 67C then it would suggest that you are power limited - either capacity of the heating element or of the power supply.
Try putting a sheet of silicone or even paper on top of the bed until it heats to where you want. Without any insulation, its probably losing too much heat to the air above the plate to reach the desired set point.