@alankilian i apparently didnt check thoroughly enough. I just checked the BL touch wiring, and im pretty sure i inverted 5V and GND... Jesus christ... Of course i connected it correct ly afterwards when i tried on the MKS.

@gixxerfast i had a spare buck converter so i tried external power from the 24v PSU, seems everything is working and running, i was able to detect card and flash firmware.

Thanks for the tips! will update when i hook up the hardware

@gixxerfast i had a spare buck converter so i tried external power from the 24v PSU, seems everything is working and running, i was able to detect card and flash firmware.

Thanks for the tips! will update when i hook up the hardware

@alankilian i apparently didnt check thoroughly enough. I just checked the BL touch wiring, and im pretty sure i inverted 5V and GND... Jesus christ... Of course i connected it correct ly afterwards when i tried on the MKS.

@gixxerfast of course, my mistake

@gixxerfast yes the area gets quite hot, quite fast, with USB connection only.

Thermistors are connected to thermistor0 and thermistor1.

Immediately after power on through USB:

10 seconds later:

@alankilian
The overheating explained is with everything unplugged and only 5V connected through USB cable.

The 3.3, 5V+, ad diag all comes on, but the diag and 3.3V fades quickly after untill its nearly off, while 5V+ is still lit

Edit: and thanks, ill try moving the jumper running it off an external 5V supply tomorrow at work and see what happens.

Hi there,

So, i am in a bit of a pickle. I recently purchased a second hand Duet 2 WiFi board - the guy never got around to use it (or gave up when he realised the work required to change on his Ender3). The board was unused but outside its warranty period being purchased around 2 years ago.

So i flashed new firmware and everything was lighting up as it should. Then connecting to the hardware, and powering up the 24V PSU.
Things were lighting up but the BL Touch sensor was not doing its regular start up deployments, and after some seconds i hear a spark. Immediately the 3.3v LED turned off.

Through alittle troubleshooting it seems the U3 chip has fried, although no clear burn marks (maybe a small indication of burn/melt through a loop), the area around the U3 chip overheats rapidly when i supply 5V through USB cable. The board is now completely unresponsive.

The following is connected to 5V:
2 thermistors
BL touch v2.1 antclabs
2 omron endstops NC

I have tripple-checked wiring, and even tried hooking the BL touch up to the old MKS board, which started up and deployed as it should.

Is there any way for me to get help with this?
The board is V1.04b.

It is as mentioned outside warranty, about 2 years old, any help whatsoever is much appreciated.

Best regards, Lars
M. Sc. Mechatronics