Battery Issues - not solved by new battery

I have a rather long saga regarding my Macbook (white, 2008)'s charging abilities.

First, my charger stopped working. I got a new one. This charger worked...sort of. About 80% of the time I was only able to charge my computer if I took the battery out, put the battery back in, and plugged in the charger. If I just tried plugging in the charger, most of the time no light would come on and my computer wouldn't recognize that it was plugged in. Taking out the battery and putting it back in worked every time, but I had to do it almost every day.

This lasted a couple of months, until one day I was unable to turn my computer on at all. I tried plugging the charger in, no light came on. I did my battery trick, and the green light came on and my computer turned on with an X over the battery icon. I took it in, they said I probably need a new battery. Fine, I've had it for 2 years and last time I checked it was at about 366 cycles.

I had to wait a couple of weeks for a new battery, and got once a few days ago. No change. My Macbook still only runs when my computer is plugged in, the battery is still an X.

So what I know is that it's not my battery and it's not my charger. Is it my logic board? Is that the most likely problem? I know it's expensive to get replaced or whatever and I want to get an idea of if it's even worth it to go back to the Apple Store for the 60th time. Also, is there any harm using my computer only through the AC adapter? My battery is still installed, my computer just doesn't realize it.

Thanks!

Oh and I have tried the SMC reset and the other reset...many times. No change.

Since you already replaced the MagSafe adapter - charger, we'll assume that's OK. You could have a defective DC input board. That would prevent the new battery from charging and give the symptoms you're seeing.

Is your MacBook covered under Apple care? If it is, let Apple deal with it. If not, you may be able to repair it yourself by changing out the DC input board. There is no guaranty the DC board is the problem, so it might be work for nothing but I'll leave that up to you.

If you wish to pursue the repair yourself go to iFixit: The free repair manual and look up the procedure for changing out the board. They also sell parts and tools.

As far as using your MacBook only on AC, that should not harm it except that you will no longer have a portable machine.