Right, just subscibed here as I recieved my N800 today and already have a problem. despite reading loads of threads from people with power up problems, there is nothing specific on this.

Firstly, I have to say that the unit is a B grade from an online supplier. Got it at a good price because the box had been opened and the unit had been used, albeit briefly.

Battery charged and everything powers up OK. All looks good.

Before loading anything onto it, I thought it would be best to upgrade to OS2008. Here is where my problem begins.

Got N800 working on windows XP machine so I can access memory card etc. Nokia Modem Cable driver installed OK.

So, with unit switched off, charger disconnected, USB cable connected to computer with Nokia software updater running and looking for device, I wirn the device on, holding down the "home" key to try to get the N800 to enter USB mode.

Not working. Worse than this, the unit does not switch on at all. After trying to connect it like this, the unit refuses to charge or switch back on.

Battery out, wait 30 mins and then I can get the unit switched on again (i read about this on another thread, something about the rft battery depleteing?).

I have tried this serveral times, with the same result each time. Each time I fail, I have to leave it, battery out, for half an hour.

Spoke to Nokia support, they suggested restoring factory settings and trying again, before contacting Nokia to retrun the product.

The thing is, it all seems to work, apart from entering this USB mode.

Anyone come across this before or have any practical suggestions. I wanna play. Boohoo.

Just reading a how to guide I found somewhere, does anyone know if it is important for the Nokia Tablet Update wizard to not already be looking for the device?
What I mean is, you have to tuen the N800 on at the very first screen you come to rather than pressing next until you come to the status screen?

Odd. I hold down the home button before I press the power button with my USB cable connected and Update Wizard looking for the device.

Solved.

This was actually the power on/off enigma referred to in other threads. It was actually nothing to do with the USB mode/cable being plugged in.

I managed to get it into USB mode after removing the battery, waiting 30 mins, reinstalling batterry, then plugging the charger in, whilst holding down the home key.

Updated to OS2008 with the software and now I have no problem at all.

May turn out to be useful for someone else. New OS rules!