Voron 2.4 bed not heating

[Yojuan]

I've had my 2.4 for a couple years now and it's been operating flawlessly. Today I got the "Heater heater_bed not heating at expected rate" error. The bed doesn't appear to be heating at all. The thermistor appears to be ok as the bed temperature on the display rises when I heat the bed with a heat gun.

Any ideas where to start? New heater?

[mvdveer]

16 minutes ago, Yojuan said:

Any ideas where to start? New heater?

Had the same problem on my Voron2.4 after happily printing for about the same time. Went ahead and ordered a new heater and bed (combination) - same error!. Turned out it was undervoltage on the Raspberry Pi causing the issue. Rewired the power to the pi with AWG18 wire with two positive inputs on the GPIO header (Pin 2 and 4) and GND on pin 6. As a test, refitted the old heater - no error. Has been happily printing since (Now I got a spare complete heaterbed for a 300mm build- Sigh)

This may be it - worth giving it a try before ordering a new heater

[PFarm]

After a few months of printing, I had the same thing happen turn out to be the thermo-fuse was open. Meter the two heater bed leads and see if there is an open circuit.

Edited August 3, 2023 by PFarm

[Yojuan]

7 minutes ago, PFarm said:

After a few months of printing, I had the same thing happen turn out to be the thermo-fuse was open. Meter the two heater bed leads and see if there is an open circuit.

Good idea, didn't think of that!

[Yojuan]

Confirmed the thermal fuse is indeed open, thanks @PFarm. Checked with the multimeter and the circuit is open. Good thing I bought spares when I built the printer.