My Dell Latitude C840 displays the same "warning: 70 Watt (20V, 3.5A) AC adapter detected" error message even with a known good 90 watt AC adapter is connected. It also won't charge the batteries anymore.
The laptop is clearly not under warranty anymore, but it was/is a really solid machine and I would like to repair it if possible. Does anybody know if this is the internal power supply that has failed and is it a replaceable component or is it part of the motherboard?
Any info on parts availability or even locations to send it for repair if I can't do it myself would be greatly appreciated.