MX7515 - Busted AC Adapter

I have owned the MX7515 ever since it's debut, great laptop, but recently it kept shutting down while the fans just start to spin at its maximum. It'll run on the battery with no problems. When the AC adapter is plugged into the laptop along with the battery, Windows keep telling me that it's 'recharging,' yet the battery percentage is dropping as if it weren't recharging. But when the laptop is off, it would actually recharge the battery at a very, very slow pace. My guess is that there isn't a constant stream of electricity going through the AC adapter, being the great electrician that I am.
I'm looking to replace the adapter, but the ones listed on the gateway site are crazy expensive with unnecessary addons. Where would be the best place for me to go?


Here's the link to the laptop on Gateway:

http://support.gateway.com/s/Mobile/Gateway/NewM520/5382nv.shtml

 

Does your laptop work without the battery but hooked up to the AC?
If so then your batterie's probably the problem, MX7515 came out in '05 no? maybe the battery is starting to die out.

 

It runs perfectly fine with the battery in. The problem first started with the AC plugged into the laptop with the battery out of the picture. The laptop would shutdown without any notice, and I usually have to wait a few hours before running the laptop again (again, this is with no batteries jacked in). Within a few shutdowns, I then realized that right before it would shutdown on me, the notebook fans would start to accelerate to full capacity.
With the battery plugged in, the fans would operate at full speed without any problems.

 

I have 2 AC adapters for the MX7525, roughly similar to the 7515 so I'm pretty sure they use the same adapter. Gateway is too expensive, I suggest you ebay a no-name brand because that is what I do and saved about 30 bucks over Gateway.