770 won't start after power off unless...
 

770 won't start after power off unless I connect the charger. Battery was full.
I thought this is firmware issue, so I download the latest and upgraded. The first time it starts fine, and then the problem come back again.
Is this hardware problem or software? Anyone experienced the same?

Strange behaviors...often linked to battery.
 

What I have discovered is that the battery/charging/power system is peculiar and not well understood by those outside of Nokia. There is also a good possibility that they don't understand it either (designer could have left for Qualcomm, retired, dropped dead--these things happen).

If the battery is weak, and you can forget the battery indicator as it can't be trusted, the 770 will perform strangely. If you have had your battery for a while, i would recommend trying a new one. Does not hurt to have a spare anyway.

Yes. I used to have a really hard time trying to figure out how to get the damn thing to power on without connecting the charger. The trick seems to be to hold down the power button for about 3-4 seconds, then release it, and wait a little bit.

Note that waiting until the screen lights on while holding down the power button does not work. I wonder if this is a feature to prevent the thing from turning on all by itself.

Of course the simplest solution is not to turn it off at all. That's what I do. ;)