A while ago, my N900 locked up. I is not bricked, and I am not sure whether it is software or hardware failing.

* The screen remains black.
* The led indicates the phone is charging (orange, slow pulse).
* An alarm goes off every 10 minutes, without sound (possibly the phone was on "silent" wen it whent down, not sure). Only removing the battery will silence that alarm.
* I attempted to flash the device, but it won't go past "Suitable USB device not found, waiting." I tried flashing it, by removing/inserting the battery, since I don't see any indication that it shuts down or starts up correctly.
* When plugging in the phone (not holding "u") in the USB my laptop sees the phone, but cannot mount it: "Nokia Mobile Phones N900 (Storage Mode)", acc to the disk-formatting-tool in Ubuntu, the device is /dev/sdb (and /dev/sdc for the add. microsd).

I think it is the hardware, more specific, the screen, failing, but I would like to know if maybe instead, it is the software.

I would also like to know if this has happened to more people.

And lastly, If, in some way, entirely resetting the device may help, I would love to find out how to do that (using Ubuntu).

phone is covered by nokia repair under a 2 year warranty If you have no luck in here take it to your nearest nokia repair centre for a free repair or replacement phone.