Moved printer, attempting print damaged board, blew another

[bass4aj]

@arkadiusz good idea. do you know what I should look for with a multimeter? I agree its likely hardware but I am not sure how/what to look at.

[Veti]

check the resistance of the heater.
then check the resistance of between the heater and the thermistor.

do this with the bed and hotend.

there should be a little bit of resistance for the heater and no resistance between heater and thermistor.
do wiggle the wires while testing.

[bass4aj]

@veti resistance between heater and thermistor? The heater is a pcb bed and the thermistor is a cartridge style pt1000 attached by Kapton tape. Or are they linked through the board somehow?

[Veti]

they should not, but the there could be a short on the hotend. when you power the hotend that would send vin to the thermistor connector.

[bass4aj]

@veti Ah gotcha. I will get those checked and post back. Thanks

[dc42]

What PSU are you using, and have you checked that it is outputting the correct voltage? Over-voltage at the input could cause U3 to fail.

[bass4aj]

@veti there is no resistance between either heater/thermistor. Both heaters have some resistance. Looks normal. @dc42 Its some generic supply that M3D put on the Promega printer. Its a 24V supply. DWC reads a constant 23.7V or so, and a check with the multimeter (after detaching from the board) shows 24.1V.

[bass4aj]

@dc42 I also just confirmed, its not U3 that blew. L2 blew. I was touching it with a pick and the whole part just fell off lol

[bass4aj]

@dc42, what kind of things could cause L2 to fail? I should also mention I saw a different thread in the forum with a similar bed issue (but not quite the same). In that post, you suggested to disconnect the bed ground and tape it to the frame. On the first board when I did that, the bed heat light stayed on, but the bed stopped heating up on start-up if that helps.

[dc42]

L2 masy blow if either U3, C6 or C12 fails. Unless C6 or C12 looks damaged, my guess is U3.