I have noticed that the D400's have a motherboard issue. A lot of people seem to be replacing them. Mine has suffered the same fate. It will not power up or even charge the battery. I have 3 power supply's and none will power it up, but the voltage is there. Mine is out of warranty. Does anyone know what is going out on these boards? When i plug in the power supply to the laptop, it causes the power supply to turn off. i then have to unplug the power supply from the wall, then plug it back in.

thanks