Lulzbot Taz bed stopped heating

Earlier today I had just finished a print and went to start a new one about 15-20 minutes later and suddenly the bed stopped heating. I tried replacing the bed with another one that was working on a different printer and it still would not heat up. Everything looks like its still attached as far as I can tell.

Does anyone have a solution or know why this would happen?

you have a broken wire or a blown F.E.T. on the control board.

To check if the FET is blown, turn on only the bed heater and looking in the side of the Control box you should see a rapidly flashing red light. this is the activity light(PWM) for the bed heater.

If you see the flashing light you have a broken wire in your heat bed cabling. If you do not see the flashing RED LED, you have a blown FET and need a new RAMBo. Or to replace the blown FET.

Thank you for this info. It helped us trouble-shoot one of our Mini’s.

Bed stopped heating. Red LED was lit when Cura was trying to heat bed. No continuity between bed heater wire & terminal block on Rambo (ergo, broken wire). Wire was indeed broken, inside the wire chase, about four inches from the Anderson connector under the bed.

We will re-route a fresh wire (no WAY I’m gonna try to fish through the chase & wire tubing!).

I am frankly a bit disappointed in the wire quality. Not very thin strands, seemingly low silicon content in insulation. Not my choice for wire that sees many thousands of flexing cycles. This machine was about two months old with about 12 hours per day of highway miles.

I wonder how many Mini’s are serviced under warranty for broken wires in the chase(s), when a wiser fix is higher quality wire in the initial build?

Thanks again for the tip, re: red LED vs. F.E.T.

I’m so happy – the rest of of my long weekend is saved because of you guys.

I came out to the garage this morning, pulled off last night’s print, started a new one, but my bed wouldn’t heat. Using the info here, I traced out which wire had gone bad, spliced in some replacement wire at the connector end and screwed it down on the board block, and the bed is heating up right now. I’m going to see if I can get a stock cable to replace the bad one, but till then, I’m up and running even if the printer doesn’t look beautiful and the wires are no longer color coordinated.

I’m so appreciative!