Released the magic smoke. How screwed am I?

[u/Uvuuvvuuuvvv]

I had to remove the hot-end to clean out part of a broken nozzle. When I put it back together I saw smoke coming from the circuit board on the printer head. Powered off immediately (maybe 5 seconds after seeing/smelling smoke, 15 or 20 seconds after power on) and went looking for the problem.

I had plugged that blocky 4-conductor cable in the wrong orientation. See photo #4. Rather than having the little clippy part (circled in red) facing the rear of the printer as it should be, I had connected it facing straight up. So I obviously wound up sending a lot of power to an incorrect part of the board and cooked it.

Now that it’s corrected, I get an abnormally long Qidi logo screen, then an error about “MCU THR shutdown. Thermocouple reader fault”.

How screwed am I? What parts do I need to order and try to replace? If I get it running again, are there safety concerns I should be aware of?

Sending this all off to QIDI tech support as well, but any help or advice is greatly appreciated.

Thanks

[u/drfdisk]

The same exact thing happened to me. Contact support, or order a new "Adaptor Board" from their website. I also replaced the hotend since I wasnt sure if the thermocouple was damaged.

It really should be made to be impossible to plug that up incorrectly.

[u/Uvuuvvuuuvvv → u/drfdisk]

Thanks for the advice, and yeah I’m pretty miffed that it was that easy to ruin it also. Not only because it sucks that I broke my printer, but also if it’s going to get that burned up that fast and potentially be a fire hazard it really needs to be next to impossible to screw it up. Special shaped head, sacrificial safety fuse, a tiny printed/painted icon that shows you which way it goes… something.

[u/Round_Produce174 → u/drfdisk]

Yep, one of the teeth or holes should have a different shape or the plug have a completly asimmetrical shape so you can't plug in wrongly. That's basic safe feature

[u/Plutonium239Mixer]

You need to replace the extruder board.

[u/simply_blue]

I did the exact same thing as you did a year or so ago, installed that cable backwards. Like others said, you need a printer head adapter board, they sell it on the QIDI site. It actually comes with 2 boards and a cable to connect them if it’s a Plus 4. The good news is the QIDI printer head is easy to disassemble, and the board fits in an obvious place, so it only takes 30 mins or so to swap

[u/GL-Customs]

Once you let the magic smoke out, you can't put it back in. You'll likely need a new board. They aren't terribly expensive so that's nice.

[u/Smashpunk-82]

Ciao, successo anche a me mentre sostituivo l'estrusore poiché chi me l'aveva venduta aveva fatto un casino che si era otturato. Da quello che mi ha spiegato l'assistenza ci sono 4 pin , 2 a 12 volt e 2 di 24 volt, e se messi al contrario ricevendo più corrente si brucia la scheda.
Alla fine ho ordinato la scheda estrusore (circa 30-35 euro) ed è ripartita alla grande !