Duet not connect in anyways - Clue: nozzle fan always on

Phaedrux

Do you still have the heat sinks mounted? Perhaps they are making contact and shorting something.

Have you removed the board from the case and disconnected everything except for the USB connection?

Give the board a blast of compressed air to dislodge any debris that may be causing a short.

Does anything get hot to the touch shortly after being connected to usb power?

genioluiz7

Do you still have the heat sinks mounted? Perhaps they are making contact and shorting something.

No, they are correctly mounted.
Have you removed the board from the case and disconnected everything except for the USB connection?

Give the board a blast of compressed air to dislodge any debris that may be causing a short.

Ok

Does anything get hot to the touch shortly after being connected to usb power?

No, nothing

As you can see below, I unplugged everything, and everything is clean and all the LEDs are on.

Now the COM10 is detected. So I tried the Fallback procedure #2 with BOSSA, but after clicked Write I clicked Verify and this warning message appeared.

What could I do now?

jay_s_uk

@genioluiz7 did the heatsinks come with the board?

genioluiz7

@jay_s_uk yes

jay_s_uk

@genioluiz7 then its a clone board and not covered by a duet warranty etc. Clone boards come with those blue heatsinks, duet boards do not.
If its none functioning then theres not much you can do

genioluiz7

@jay_s_uk Since I bought it from someone else, could it be that they were added later? I believe that is original.

I said yes becouse when I received the board they were already mounted. Ma non so di più.

jay_s_uk

@genioluiz7 i mean you could add them later.
The ultimate way to tell would be remove the heatsinks on the main MCU and see if theres any evidence of a sticker.
Having the heatsinks on the drivers and MCU do nothing anyway as the board takes the heat away

dc42

@genioluiz7 ignore the DIAG LED. On Duet 2 it is shared with the Z probe command pin, so it doesn't mean anything, except that for certain startup errors it will flash an error code.

When you flashed the board using Bossa, did you remove the Erase jumper before pressing the Write button? If you don't remove it then the write will fail, leading to lots of verify errors.

genioluiz7

@dc42 Thanks for the suggestion on the LED Diag.
Yes, I followed the instructions about that. I can show what I did in particular:
Turned off Duet
Put Jumpering the erase jumper.
Turned on Duet for few sec.
Than turned off.
Removed the erase jumper.
Turned on Duet again.
Then pressed the Reset button.
Opened Bossa and selected COM10 and checked boxes Erase all, Lock, and Boot to flash, then press Write. The write process worked

After I clicked Verify and at the end I got the warning message (Verify failed Page errors: 1021 Byte errors: 63923) and I stoped

dc42

@genioluiz7 if the Erase jumper was definitely not in place when you ran Bossa, then sadly I think the flash memory of the main processor on the Duet as been damaged. The only other possibility I can think of is that the 3.3V rail is low, perhaps because something powered by it is drawing excessive current. If you have a multimeter, you could measure the voltage between the 3.3V and ground pins of one of the endstop connectors.