USB/network failure

[davidmam]

I have the Raspbian image (the latest prior to the 512Mb update). I've been running the Pi fine for a while but never more than for a few hours. I have been trying to get a particular project running (temperature logging via an Arex tl-500) but run into a problem. The Pi would randomly freeze - just drop off the network and only be recoverable by a reboot. This was both on wired and a wireless USB dongle. Now it won't start the network at all. Having plugged it into the TV to get an HDMI console, I can see it is booting but I get an error on the dwc_otg module (it scrolls too fast to catch) and the network fails to initialise. The Pi is unresponsive to the USB keyboard. I then somewhat foolishly tried my new 512Mb Pi. That shortly went the same way. Before the first one failed I was unable to see the peripheral (the TL-500) attached to the USB with lsusb - it had disappeared.

I noticed that the USB connectors did get rather warm (I'm running the Pi from a powered USB hub)

I don't have any console access via serial so cannot investigate further. I have tried several different card images with no joy.

So I now have two Pi that are useless as they cannot communicate with anything. This was a bog standard off the shelf USB powered hub. No other mods.

Any hints on getting things up and running?

Or is the Pi really this fragile and really not fit for use as a general purpose computer but needs to be wrapped in cotton wool? I'm really keen on the Pi and this is a real frustration.

[bgirardot]

You can see the boot messages with this command at the command line:

dmesg

That should at least help you find the error message you saw scroll by.

[davidmam]

I get no response from the keyboard so logging in and running commands is a non-starter.
Likewise no response from the network.

[bgirardot]

Ouch, I missed that part, srry.

I am sure you will get them back up and running, it is just going to take someone with better troubleshooting skills than me.

If I understand correctly the new 512 pi worked fine for a while and now it is the same boat, no keyboard, no network?

[davidmam]

OK, My bad. I had inadvertently used a different microUSB lead (a very cheap one) and that was the issue.

The power supply issue really is something that needs addressing to be more consistent rather than abusing an existing standard.

[captn]

So I now have two Pi that are useless as they cannot communicate with anything. This was a bog standard off the shelf USB powered hub. No other mods.

That doesn't say anything. You should check the Voltage between TP1 and TP2 (5V) or better, buy an extra 5V PSU for the RPi.

Maybe the file system is now corrupt, reflash the image and test it _only_ with a keyboard plugged directly (without the hub).

[bgirardot]

OK, My bad. I had inadvertently used a different microUSB lead (a very cheap one) and that was the issue.

The power supply issue really is something that needs addressing to be more consistent rather than abusing an existing standard.

Glad to hear they are working again.

[davidmam]

It all seems happy - cheap cable with obviously too high a resistance.
I get the Pi to a state I like then take an image of the SD card to save having to go through all the setup again.

..d