URGENT: Thinkpad not charging/BIOS low bty.

Ok first I'm an idiot for not backing up my data as I've been wayy too busy(now I have to do it the hard way and remove the HD, etc...).

First for the last 1 week and until today my Thinkpad would have a hard time charging. I would plug it in and it wouldn't charge. I would have to snuggle it into the plug to make it charge sometimes forcibly. Now it won't charge at all unless hacking/snuggling it as I can't boot into Windows/Linux anymore as the BIOS gives the critical-low-battery warning and shuts off. I doubt it's a plug problem since I look at the port and pins and they look normal (not damaged, twisted, etc...) from the naked eye. The Thinkpad will run without the battery when plugged in and it doesn't charge that way unless I hack it again as stated above and won't run either. When hacking it during the last week I would have to hold the plug in a certain position in the power plug to make it charge. Eventually even that started getting harder to do. Now the Thinkpad is in a state of low-power/can't boot and I need to permanently fix this problem.
I have come up with 3 theories of defective parts:
1. The power brick
2. The battery
3. Internal circuitry/motherboard.

#1 & #2 are easy to replace and since I can't boot the computer up without the battery plugged into the wall I have a feeling it may be #1 or #3. This is due to the fact that I ThinkPad battery manager always said I had 85% health of battery left and could go for another 2 years I think. First of all right now I'm going to try getting another power brick (someone else's, I do have a few people I know with Thinkpads) and see if that fixes the problem. If it doesn't I'll try getting a compatible battery (this is a little harder) and see if it fixes the problem but I doubt it as I can't boot it up WITHOUT the battery plugged into the wall. #3 is going to be long, arduous and expensive. I really hope it's not #3.

 

UPDATE: It now charges if I rotate the plug. Definitely something to do with a loose plug. Now the question is it the plug or the plug socket on the motherboard?

 

This is probably something you would have to test and see.Do you have an universal power adapter to try it out with, perhaps another thinkpad AC charger?

You might have already tried this, but did you check the condition of your battery? If its anything other than "Good" then that would be the culprit

 

It could be the socket on the thinkpad. I dont know what model you have, but on my R61 the jack plugs into the motherboard so its easy to replace. just so you know.