Per the subject, my machine runs fine with the AC adapter plugged in, but if I unplug it, the machine shuts off immediately. Similarly, if the machine is off and the AC adapter is unplugged, pressing the power switch does nothing. I've updated the BIOS. The battery indicates 100%. A non-competent person at Dell Tech Support just said to send it in for "Depot Warranty Service," suspecting a motherboard issue. Before I take that step, I'd like to make sure I've exhausted other options. Any other suggestions?
Thanks, Mike