Your adapter sounds fine, the green light indicates it is working ok. I'd suspect eitther the battery, they only have a limited life of a few years (some less then that) or a fault in the battery charging circuit on the motherboard (ie: a short somewhere). Check the pins where the battery makes its contacts in case anything looks bent etc

I'm having a similar problem...  My AC adapter's green light started going out for no reason.  I just got the motherboard in my Inspiron 8200 replaced at the repair depot and got it back on monday.  Now 4 days later I'm having this issue.  After the AC adapter goes off, the laptop goes into battery mode and the power supply stays off.  The only way to get it to come back on is to unplug it and wait about 30 seconds or so and plug it back in.  Unfortunately, it goes back off again after a few more minutes of use.

I just had it off for a few minutes with the batteries out and switched battery sides and plugged everything back in and am hoping it will be fixed.   However, I read a mod's post in another thread that if the green light goes out on the AC adaptor when plugged into the laptop, that it's a motherboard issue. :(

Hi

Have you tried to replace new battery?  because I can't even use battery when AC adapter is not plugging. about switch battery around, my battery can't switch, I don't know what you mean by switch it.