I've seen the other posts - I'm having a similar issue with the MKR WiFi 1010 - if I piggyback it on the Vidor 4K it powers up; but by the USB itself nothing. I've checked the 5V pin on J4 - when the USB is plugged in - there's no voltage on that pin. When piggybacked on the Vidor 4K - I read 4.997 Volts on the 5V pin on J4.
So, it appears maybe there's an issue - I wonder if there's a race condition with the ARM enabling USB and how this board powers up and/or the USB connector itself has a connectivity issue.
Would be nice to know what the 'ruling' of this has been by Arduino since it appears to be a common issue with these boards. And, of course, I've tried hitting the reset switch when plugging in but nothing happens. It appears the USB's 5V and the board's 5V are disconnected.
The cables/USB ports I've been using power up the MKR Vidor 4000 just fine.
Sorry, I missed that. All I can tell you is my MKR WiFi 1010 powers up from USB with no problem. I have noticed that when using a long cheap USB cable it won't be recognized by my computer, though it does get power and that cable works for other boards. When I use a higher quality cable it works fine.
I contacted support; waiting for the replacement team now to give me details on how to get this one replaced.
Not sure why the support person didn't supply that.
But this unit was 100% DOA using the USB port.
So, I did get a replacement - and when I attached with a USB cable the Green power LED did come on along with the Amber LED - at least at initial power up. The first board I received - the Green Power LED never came on with the USB cable plugged in - I guess that should be question #1 for those that are helping troubleshoot this issue - but the replacement unit appears to have an issue with Serial Port 1.
I have a sketch for the MKR Vidor 4000 and the Uno WiFi Rev2 that both work with identical code regarding Serial Port 1; so it does appear Serial Port 1 on the replacement unit is having a problem.
I will attach to a scope and take a look - but looks like the replacement unit has an issue as well.
The board was shipped in a 'soft package' and the packing appeared to be crunched a little when I opened it - I didn't think there was any damage but maybe the board suffered some damage due to this. Not sure.
Update - I did the NINA firmware update - tested again - and Serial Port 1 is fine now. Not sure at this point why I wasn't able to get Serial Port 1 to work initially - but appears all is well.
Thanks to the Arduino staff for the prompt replacement - good response from all of you appreciated!