I tried exactly this. It doesn't respond at all when holding the U key down. It will just shut off and restart again automatically. According to a few others on here I'll try charging the battery with an external charger once it arrives (ordered it on ebay) and post the results.

I'm also completely stuck at this point.

* N900 died after on-line upgrade attempt (yes, battery was full).
* Got flasher tool, fiasco image
* Put N900 on charger. Yellow light on. Eventually it switched off.
* Then started flasher-3.5 -F <name of image> -f -R
* Got message 'no suitable USB device found', as expected
* Plugged in N900. Yellow light on. Did not go into flashing mode.
* Same, but pressing 'u' on N900 kbd, then plugging in cable. No go.
* Also tried removing battery, plugging it in while connected. No go.

Basically the problem seems to be that the N900 won't go into flashing mode, whatever I do. I have checked 'dmesg' output on my laptop and there is no indication that it is even plugged in. The only time I see any activity is if I remove and re-install the N900 battery, then there's a very quick 'new high speed USB device..' followed by 'USB disconnect'.

I have used this same laptop to flash my N800 several times, without a problem. I also tried to flash the N900 from a desktop computer, to no effect.

Does anyone sit on any idea not already posted in some thread or mentioned on the wiki? I believe I've tried everything. At this point my N900 looks totally bricked, the only sign of life is that it appears to be able to charge. There isn't a flicker of life on the screen.

When you hold down U and plug in the cable, does it go into USB mode (non-backlit Nokia logo + USB icon)? If so, the N900 should be capable of being flashed. What OS are you using for flashing? I couldn't get my PC to recognise the N900 using flasher on Windows XP, but using a bootable Linux flash drive, it worked fine.

No, it doesn't. The screen is always black. The yellow charging light goes on as soon as I plug in the cable. (even though it has been charged until light goes off, just before attempting flashing).
I'm using a Linux laptop. Also tried a Linux desktop. The laptop is what I used when flashing my old N800.

The flash-3.5 tool is apparently waiting for an USB event to detect the N900, but it doesn't see any - and 'dmesg' output doesn't indicate that it's been plugged in at all.

I have successfully used the same laptop to access the N900 filesystem, through the same (original) N900 USB cable, before I started the failed 1.1 upgrade attempt.

By "until light goes off" do you mean until it goes green?

Actually, it doesn't go green. When I plugged in the charger the yellow light turned on, and after a while (could've been half an hour or more) the yellow light simply turned off. It never went green. The yellow light is the only sign of life on the N900, the screen never flickers on and the power button doesn't work etc.

I'll be away for a few minutes, going to try a 3rd computer just for the heck of it.
EDIT: Did that, no go.

That doesn't sound like it's charging at all then. When charging, the light should pulse yellow (slowly), then go green when it's fully charged. I'd suggest charging the battery up outside the N900 (desktop charger or compatible phone) and trying flashing again.

Unfortunately I don't have anything else to charge the battery with. But it was fully charged before I started the 1.1 update attempt, and it's strange if it should have been run down so extremely quickly (fully charged before the N900 upgrade attempt, which failed quite quickly, and after that I left the battery out while waiting for the download server to be available - just because I didn't want anything starting to discharge the battery). I'll see what I can do though - thanks for the suggestion.

Edit: This is what the openpandora folks got right - there doesn't even need to be a battery in it. AC is enough.

Have you tried the reset for firmware loads by removing the battery, then plugging in the USB cable to your PC and N900, yellow light comes on, then put the battery back in? I had to do this several times...

My upgrade hassle to a solution is in this post. Only other thing to add is I would have to power down the N900 after each reboot. It stayed on technically, even thought the screen was blank and it appeared as good as dead. Holding the power button for ~2-3 seconds would illuminate the white status light and the brightness would slowly fade. The black blank screen would change to a different shade of black (easy to miss) and I'd know it was then really "off". This took <10-15 seconds total for the power off. Only then could I hold down the "u" keyboard key and plug it into the USB port to start the flasher.

@speednut: Uh yeah, i had the same behaviour. It looks like off but the screen has to get balck-er.

@Ta-t3: It looks like your phone is one of the few really bricked. You also can't get a reaction with your power button i assume? When did the update fail? Or did it go all the way through? I would pass it back to Nokia and get a new one...

Anyways, quite a few ppl are reporting bricked devices after Pr1.1 now. It really is a shame.