Insp;rion 1750 AC adapter issues

When I purchased the Inspiron 1750, I got an additional AC adapter so that the laptop could be plugged in at 2 different locations.  (I've had them for over a year now.)  When I plugged the AC adapter in, I got a message that the AC adapter could not be recognized and to make sure it was plugged in and it was a Dell 65W AC.  After reading a bunch of articles, I removed the battery, replaced it, then it was able to recognize the AC adapter and the laptop was charged.  Then I went to use the 2nd AC adapter and had the same problem.  I performed the same tasks and the 2nd one now works, but the first one doesn't work again.  When I tried to update the BIOS, I get a message that both the AC adapter and battery must be plugged in, which they are.  I tried to do the update with the AC adapter that COULD be recognized.  I'm assuming that the problem is either the battery or the power board.  Seeing that it will charge, but only with one AC adapter, I'm not sure what the issue is.  I know they both worked in the beginning.  Any help will be greatly appreciated!