well looks like i am in good company...I too am now suffering from the factory AC Adapter failure. I have checked my BIOS and the AC Adapter is now unknown. Of course the warranty on my 3500 dollar machine expired last month so begins the game of nickeling and diming the customer.
BIOS is A10 and before someone tells me to update i typed in my Service number and updating is not an option. So other than never buying a dell again any known workarounds.
I have already shelled out the 150 for a replacement adapter and please do not waste my time with holding the power button wiggling or unplugging all peripherals....it doesn't work. Should have known better when the company uses my middle name as my first name on all correspondence it sends. I really wish computers broke because I abused it instead of garbage components. Suppose this is more rant than assistance. If anyone has any new advice please let me know. With my luck it will be the motherboards jack in which case i think I would rather use it for target practice than waste my time with this company.