MBP charger? logic board?

Not sure if this is a logic board issue or a charger issue but here are the symptoms...

MBP charger light has been going off and computer shuts down instantly. Sometimes date/time reset, sometimes fans run on high. It will restart without charger plugged in and battery holds a charge well. When attempting to plug in again, sometimes it works or it either won't light and charge or computer turns off again. It seems as though if you move the charger just right it will turn off again. Have done multiple SMC resets, sometimes it works, sometimes it won't reset. The charger looks new, the computer was bought in Dec. '10 and doesn't travel much. No stuck pins, clean.
I brought it to a genius bar a couple months ago and they said nothing was wrong with it, but maybe it might be the logic board going... Crazy for a year old computer in my opinion. After 4 weeks of owning the thing the hard drive crashed...

First question: Do you have Apple care? If so, take it on back to the genius bar and have them diagnosis it.

Have you tried running the Apple Hardware Test?

No I don't have apple care. I couldn't afford it when it was due and honestly am wishing I had found the $ somewhere after learning of all the troubles a mac can have...
I ran the extensive hardware test, nothing found. When I took it to the genius bar they found nothing either and all they said was "might be the logic board failing". Wouldn't that show up on the testing though? Maybe its a faulty connection between the charger and the computer?

The Apple Hardware Test is not definitive, unfortunately. Intermittent problems are not likely to show up unless the entire unit is stressed. That's why Apple will sometimes opt to change out a Logic board rather than wrestle with an intermittent problem over time. It's just easier and less costly in the long run.

Your choices are rather limited. You can keep going back to the genius bar but it's likely they'll want to change out the Logic board and charge you for it. Or, you can put it up for sale as having problems. Use whatever you can get out of it to buy a new machine. Not an ideal solution if you're short on funds...