Currently Being ModeratedApr 17, 2013 7:11 PM (in response to Edzqrd)
There's only 4 major components in the charging circuit: power adapter, dc-in card, battery, and logic board. You've said the system runs fine on battery power, and charges OK when the system is off. So power adapter would seem to be OK and battery would seem to be OK (although that's a fair amount of cycles on it). You could try a new battery, but my money would be on an intermittent issue with the dc-in card or logic board. Unfortuanately, there is no test you can run, with the power circuit you replace parts, typically starting with the least expensive.