USB not working

[trt]

USB problems are caused by cheap low quality power supplies.

I have 2 boards.

First Parallella is powered by a dlink 5v 2a that "loosely" falls into the specs. I wouldn't call it high quality. USB does not work on this board. I believe that USB doesn't work on this board due to this power supply, everything else works great on the board btw!

Second Parallella is powered by a high quality 5v 3a. USB works perfectly with a mac slim keyboard through a cheap 4 port unpowered hub with a LED on it that does light up. I haven't used a mouse with this board I will explain why.

The reason I haven't used a mouse with this one is because the other board when I plugged a mouse in the usb stopped working completely. It was a Microsoft mouse, should of known that plugging ms carpola would kill the Parallella!

I really think I want to use a powered hub and just use a power strip to control both the Parallella and the usb hub.

[leon_heller]

I'm using good quality Stontronics power supplies. Here is the spec. of one of them:

http://www.rapidonline.com/pdf/85-3940.pdf

[TimW]

[TimW]

Okay, I checked my devices, and the most they can draw is 200mA, and somebody else has measured and the one I've mostly used really only draws 22mA. That should be safe enough.

[TimW]

So I have 4 boards, none of which have USB working. Two of them worked intermittently, but nothing recently. I've tried with/without hubs and I verified that I can SSH into them. So, will the USB ever work? Is there a potential firmware/OS upgrade that will fix it? Or do I have to resign myself to never being able to use the boards in a meaningful way other than via SSH?

[shodruk]

I recommend 3A or more PSU.
Maybe 4A, 5A is better.

[turing]

Hi:

Sorry if this is too long a post, but I wanted to provide details on my experience. I received my cluster on Friday, three days ago; I checked the contents to make sure that I had everything that I needed and identified what documentation I'd need to read / view before starting. On Saturday I purchased a surge-protected power supply to use with the (supplied) power adapters and did a dry run of my procedure, using my Raspberry Pi 'cluster'.
On Sunday, I installed the current O/S image on an SD card, inserted it in one of the boards and, following the quick start instructions, successfully got it running - HDMI was fine, USB was fine [using an unpowered hub, as recommended, with just a keyboard and mouse attached], the Zynq wasn't particularly warm (I had, of course, put on the heatsink before doing anything else...) - so I proceeded to configure the SD card, installing the software that I am going to use, setting the timezone, password, et cetera. After a couple of hours, the Zynq was a bit warm but, otherwise, everything was normal.
I then cloned the SD card to the other cards and started testing. Each board passed, going all the way to the desktop after logging on.
I then began assembling the stack, as per the documentation. With each board, I attached the standoffs, installed an SD card, connected the USB hub and HDMI cable and then powered on the board - each started up fine. Note that I only powered on one board at a time, but the ethernet cables were attached to all the boards. All the power adapters were lined up the same way.
Finally, when all four boards were checked out, I connected the power adapters to all the boards and powered on the whole system.
I could not login to the board to which the USB hub was attached. In fact, neither the keyboard nor mouse would work, and swapping them with other keyboards or mice made no difference. Neither did using a different USB (unpowered) hub.
When I decided to try connecting the USB hub to a different board, I nearly burnt myself on the standoffs - not only were they scalding hot, but the boards were very warm, all the way to the edges and even the SD card was warm!
I then turned off the power bar - I had only powered the cluster for the amount of time that it takes to boot to the login screen - and let everything cool down before disassembling the stack.
I then tested each board - and none of the USB ports work now. The boards get to the login screen, and I can SSH into every board, but USB is 'toast' - which, considering how hot the system got, is not that far off. I had originally planned to operate the cluster as a 'headless' server, but now I'm very concerned about the potential fire hazard if I were to do so, since I'm not sure how big a fan it would take to cool the standoffs to just-warm-to-the-touch. If it takes a 20W fan to cool a 2W board, there's something very wrong going on.
Has anyone else experienced this?
What should I do next?

[jabberlope]

[timpart]

[turing]

1) I didn't make any changes to the boards.
2) Each of the power adapters was one provided as part of the 'mini-cluster' kit.
3) All the cables were from the 'mini-cluster' kit, except for a single ethernet cable that ran from the switch to another switch to provide WAN access.
4) The keyboard / mouse / power adapter combination worked fine for any individual board, until I constructed the stack.

Note that all the boards showed reasonable activity - the board LEDs were blinking, the ethernet was active, et cetera, even while generating copious amounts of heat.
After disassembling the stack, I tested each board individually - they all booted to the login screen, but the USB port was no longer functional. I could SSH into each board, as I tested them, to confirm that processes were running.
Is it possible that one (or more) of the power adapters did not provide sufficient power, causing a form of ground fault? I suspect that, since the videos of Parallela stacks show bench power supplies, rather than using the power adapters, that there may be issues with using them with the 'mini-cluster'. I plan on acquiring a power supply that can provide at least 3A per board, and use it rather than the four power adapters that were supplied...

I'd very much like to get the boards working properly again, but I suspect that the USB controller is FUBAR'd; how do I arrange for RMA, and who should I contact? - the only non-sales support contact is via the forums, which is why I've posted here.