power button only works with power chord unplugged....

[wrybread]

Strange problem: on my T30, I can't turn the laptop on unless I unplug the wall power. Can anyone think of a reason for this?

[truk]

Does it have any other symptoms? EX. Dies when plugged in, battery charges slow/not at all, heats up excessively when plugged in.
Also, have you tried a different power supply, power cord, and outlet? It has been known to happen when the power brick is getting out enough voltage/current to charge the laptop, but not initialize and sometime run it.