61-33 chip blow out

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

@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

@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 ..

@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

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.

dombee

@dc42

Bossa program shut down
i try with sam -ba and it's said enable to connect
Nothing seems hot

dc42

And the LEDs?

Did you remove or replace the SD card? The old one was probably blown.

dombee

yes i replace them