Hard time diagnosing A1181 issue. Bad DC-IN, RAM or Logic Board?

Hello!

I am trying to diagnose a friend's Macbook. I think I may or may not have resolved the issue and would just like expert opinions on the matter.

Basically, what happened is she said that it was dropped, and ever since then it has been working only about 40% of the time, meaning that when I power it on, 60% of the time I get the "you need to restart your computer. hold down etc..." error message.

I took the Macbook apart awhile back, and noticed that one of the RAM slots was broken, and wouldn't seat the RAM properly. The computer was upgraded to 10.6.8 and is running only 512 of RAM from just one slot.

I am almost positive that the RAM is the issue; however, I was just wondering why it would work some of the time. It is completely random, which confuses me a bit. I did leave the other RAM chip in the broken slot, thinking that the computer may recognize it. I didn't jam it in or anything, but it definitely didn't seat as proper as the other slot. -so this may be the case, where the computer is having a hard time with the broken RAM slot with a chip half-seated.

Obviously some other parts could've been damaged when the computer was dropped, but when I opened it up, I couldn't find anything else that was wrong with it. Before discovering the RAM slot issue, I even bought a new battery, and so I know it is not the battery.

The AC adapter and DC-in seem to be functioning a little erratically as well. Sometimes the light on the adapter is green, while other times it is amber, and then other times there is no light at all.

If the RAM slot is the issue, would it be possible to upgrade to @ least a gig of RAM, running off of just that one slot?

Any help would be greatly appreciated.