Hello,
I searched the threads but could not find anything matching what I am experiencing. Hitting the power button, plugging in the charger, plugging in the usb all produce no result.

Removing the battery and connecting the charger briefly displays the "charging light"

Previously the phone was in my pocket around 90% charge. A few days ago I had a weird error. The power level went red (it should have been around 15% based on recognizing my usage levels mentally without checking the battery level display anyway...) I hooked it up to the charger until the display light went green. The red power level and beep were still there so I rebooted and everything was fine.

There doesn't appear to be any trauma to the N900 so I don't know if the N900 hardware failed or if I simply need a new battery.