61-33 chip blow out

[dombee]

After plug the micro usb cable (with 12v on) the bord smell burn.
After verification, the micro usb port burn and a chip i can't identify.
Some one have any information about it and if it can be purchase somewhere?

thanks for your help

[T3P3Tony]

@dombee thats the 3.3V LDO regulator its "U2" on page 3 of the schematic here:
https://github.com/T3P3/Duet/blob/master/Duet2/Duet2v1.04/Duet2_1.04b_Schematic.pdf

Its a AP7361C-33E-13

Can I ask why you plugged in a micro USB cable with 12V ?

[dombee]

Because im stupid...
I don't remember the IP adress of the board.
I want to connect the board to the pc to see the adress on yat.
But i was to lazy to turn power off

[A Former User]

Plugging in the USB cable with Vin applied to the board shouldn't be an issue. I think maybe Tony read your post as the USB cable being a custom one with 12v instead of the usual 5v, so odds are the board shorted something else as a result of you plugging in the cable, not directly causing the problem.

[Dougal1957]

I think we thought that you plugged in the USB but it had 12 v on it I am thinking maybe you mean the board was powered by 12V and then you plugged in the USB Connected to your computer is that correct?

[dombee]

@Dougal1957 exac

[dombee]

After replace the piece.
The usb port don't work.
When i start the board with only the 12v, the wifi module and the sd card reader
become very hot.
I think it's the end of that board

[dc42]

@dombee said in 61-33 chip blow out:

When i start the board with only the 12v, the wifi module and the sd card reader
become very hot.

When there is excessive voltage on the 3.3V rail, the SD card and the WiFi module are usually the first components to fail. I suggest you remove the SD card from the socket and throw it away, then if possible check the voltage on the 3.3V rail. Then fit the Erase jumper, press Reset, and see if you can get the Bossa port to appear on the PC. If it does, then your board can probably be recovered by replacing the WiFi module.

[dombee]

@dc42 said in 61-33 chip blow out:

when I connect the usb cable, no led lights. Can i erase anyway

[dc42]

@dombee said in 61-33 chip blow out:

@dc42 said in 61-33 chip blow out:

when I connect the usb cable, no led lights. Can i erase anyway

No. Assuming the cable is OK, that means your PC has cut power to the USB port because it is drawing too much current. That's probably because the faulty WiFi module is drawing too much current.

[dombee]

I guest the shield of the usb port should be grounded?
when i plug a usb cable and check the ground i got nothing.
Does im right?
On an other side, when i plug only 12v PSU i got +/-3.3v on the 3.3v rail

[A Former User]

@dombee said in 61-33 chip blow out:

I guest the shield of the usb port should be grounded?

(on) my maestro (the usb) isn't, the microSD slot is, and the ethernet isn't - which seems to make sense to avoid ground loops.

[dombee]

@bearer
I mean conductivity not 3.3V
When i try with 2 working port i have conductivity

[T3P3Tony]

@bearer on the Maestro ethernet shield should be grounded through a large resistor (1M ohm)
https://github.com/T3P3/Duet/blob/master/Duet2/Duet2Maestro_v1.0/Duet2Maestro_Schematic_v1.0.pdf

[A Former User]

@T3P3Tony said in 61-33 chip blow out:

@bearer on the Maestro ethernet shield should be grounded through a large resistor (1M ohm)

confirmed, but outside the measurement range ..

[A Former User]

@dombee said in 61-33 chip blow out:

@bearer
I mean conductivity not 3.3V
When i try with 2 working port i have conductivity

working and being correct isn't always the same thing This is for the Wifi, coupled though a cap:

[dombee]

It's official, the ground on the usb port don't works
il plug the cable an put the ground usb wire to an other place and its working

[A Former User]

That has nothing to do with the shielding as such. More likely the usb socket is bad, or the ground pin is poorly soldered to the PCB. (ruling out issues with cables or the far side).

Could have been damaged by the initial incident as well.

(In fact if the usb shield was grounded you'd have the supply current run through the shield (no bueno) which is part of the reason its decoupled with the capacitor as shown in the schematic.)

[dombee]

i juste replace the wifi module
i erase the firmware
in port com i see bossa program port
when i selec the right port in bossa he shut down.

when the usb was on i vas 4 led open:

red 5v+
green 3.3v
red between reset and usb
red dial

[dc42]

@dombee said in 61-33 chip blow out:

i juste replace the wifi module
i erase the firmware
in port com i see bossa program port
when i selec the right port in bossa he shut down.

when the usb was on i vas 4 led open:

red 5v+
green 3.3v
red between reset and usb
red dial

What shut down: the Duet? Did the red and green LEDs go off? Were any components on the Duet getting hot?

The PC will shut off the USB port if it detects that too much current is being taken from it.