this just happened yesterday. N800 was on and charging, then I went to check something and it was off. Tried to power it on, blue square lights up, boot screen turns on, and then turns off. Nothing else happens.

The same repeats everytime I try to power it on

any ideas?

Try removing the battery for a few minutes. Is it getting to the loading bar at all?

wasn't coming on earlier, I just put it on the charger and the charge icon came up, and it actually loaded up when I pressed the power button

now it's working so I guess you can disregard this problem, hopefully it won't happen again