The other day I was using the laptop and it started to run low on battery, so I put it to sleep and left it unplugged. When I came back, I opened the lid and the computer had run out of battery, so I plugged it back in. However, even after being plugged in, the MBP wouldn't boot. After leaving it a while to charge it still wouldn't boot up. It will respond to the power button - the sleep light flashes, and then goes dim, the DVD drive does it's thing, the fans spin up for a second (I think), and I think the HDD reads for a second, but I never get a chime, and the screen never comes on. I've tried resetting the PRAM, holding the power button with all power removed from the machine, and changing out the RAM/only using one stick, and the problem persists. Now, just to make the problem more interesting, the machine has actually booted up a few times since. Once the day after it initially failed it had been plugged in, powered off, and it just booted up like it didn't have a problem. Shortly after I closed the lid to see what would happen, and the problem came back - it wouldn't even wake. Since then, it's booted about 2 other times and it works perfectly as long as I don't let it sleep. Now, I'm hoping that the problem is something I can replace, because I doubt I can pay for a repair, or get it done for free - the MBP is well past warranty, and I've opened it up myself for repairs and voided it anyway, plus it's pretty dinged up by now. Is there anything I can try to fix the problem?