If I have my N900 powered off with no battery inserted (no power at all, battery out of phone for more than 10s) and nothing connected to the USB port and then insert the battery the phone displays the Nokia logo for about 5 seconds (with the screen being in that very dim almost unreadable state) then the screen goes blank and the status LED goes bright yellow then fades out.

If I then press down on the power button, the exact same thing repeats itself (nokia logo on very dim screen, yellow status LED)

However, if I plug the phone into either my wall-wart charger or my PC USB cable (regardless of whether I have the cable plugged in first or the battery in the phone first), the phone then boots into act-dead mode (which is exactly what it should be doing when its powered up with cable plugged in).

It seems like somehow the hardware (or BME or something) thinks there is a phantom USB cable plugged in when there is most definatly no cable plugged in (which causes the phone to start up in the wrong mode) but then it find it cant get any juice from the charger it thinks is plugged in so it kills the phone (hence the yellow status LED).

I am 100% certain its not a low, flat or faulty battery causing this to happen (I have tried multiple batteries both of which are confirmed "good" and at least one of which should have plenty of juice left in it)

I am not running the BME replacements or any modified kernel so those cant be causing this.

I dont see anything strange in syslog when I boot the phone with the charger/USB cable plugged in and I dont even know if the hernel (much less syslogd/klogd) are starting up when I power it up with no cable (and it does the "nokia logo then yellow LED then off" thing)

Does anyone have any ideas what I can try, I really need to get my phone working again to the point where it boots with no cable/charger plugged in...