Another MKR1000 not detected thread

Hoping I just missed something here, but I've got two MKR1000 that are not detected when plugged into USB and one gets warm really quickly after being plugged into USB.

I purchased several of the Arduino Engineering Kits for use in our labs and all the MKR1000, except these two, seem to work and are detected immediately when plugged in. Makes the classroom less interactive having these two boards not functioning right now, so the students are a bit bored, so any help would be greatly appreciated.

Specifics.....

Computer: Windows 10 (18363.592)

USB ports: 2 and 3

IDE - 1.8.11 - SAMD - 1.8.4

MKR1000 -

Plug boards in, and power LED comes on, no other LEDs

Swapped USB cables (used ones that came with the kit and one that did not)....nothing

Swapped USB port...nothing

Swapped computers....nothing

Double clicked the reset button....nothing

Held down the reset button...nothing

Plugged in a "good" MKR1000, it detects, verify connection and upload a simple sketch...unplug "good" MKR1000, plug in "suspect" MKR1000, change nothing else.....nothing (not detected)

Scanned the forums, tried a firmware update, but since it cannot detect, I cannot upload anything.....so here I am.

Help!

You could try burning the bootloader on them. There is a chance the problem is caused by the bootloader somehow having been erased. I documented my experiences burning the bootloader on MKR boards starting here:
https://forum.arduino.cc/index.php?topic=628410.msg4255482#msg4255482
You will need a programmer or adapter that fits the 2x5 header on the top of the MKR1000 to make the connections between the programmer and the MKR1000. I bought one of these for that purpose:

The truth is that there is a good chance the boards are dead. In my experience, a certain amount of fried hardware is an inevitable part of the learning process. I'm sure the loss rate is higher in the classroom.

Thanks, I give the bootloader a look.

pert:
The truth is that there is a good chance the boards are dead. In my experience, a certain amount of fried hardware is an inevitable part of the learning process. I'm sure the loss rate is higher in the classroom.

That's what I was afraid of...dead board. I understand there might be some loss rate as the students learn, but these boards were new and fresh out of the kit and just plugged in with the provided USB cable. So that's would be a little frustrating.

Oh, sorry, I didn't realize you were having this problem right out of the box. That's no fun.

The MKR boards come with their pins inserted into anti-static foam. This foam is conductive so you need to remove it before using the board. I've never had the foam cause a problem with the board being detected, but it's definitely worth a try.

If you have any shields/carriers/wiring/modules/etc. connected to the boards, disconnect it and see whether this makes the problem go away.

If you still have the problem, please contact Arduino support via this form:

Unfortunately this has been my experience once as well. Right out of box tried everything nodnermot had.
This is my 3rd MKR1000 and also have MKR1010 that never had this symptom . I experienced other intermittent USB issues such as those listed in other "USB will not connect threads" but never dead out of box :frowning: