My GPU doesn't work, but the rest of the laptop is fine. Help?

Story time. So, about a month ago, since my laptop had been throttling, I decided to take it apart and clean it. I got to the point where I took the whole motherboard out, flipped it over, saw the heatsinks/fans, and decided... I'll do this another day. But when I put it back together, it wouldn't turn on. I sent it to toshiba. (2 weeks) later, they told me that it worked fine for them, but they couldn't login to my windows because I didn't give them the password. Whatever. I told them to send it back.
I got it back, and to my surprise it turned on. I reinstalled windows because I just wanted to start fresh. My laptop has optimus. I installed my intel drivers, then the nvidia drivers. All went well. I downloaded furmark, it ran smooth, still throttled, but I honestly did not care. However, I installed steam, and it asked if I wanted to participate in the hardware survey. I said sure! BSOD.
Wut.
I turned it back on, it failed to boot to windows. Turned it back on AGAIN, and this time it worked. I decided to not do the steam hardware survey. I downloaded a couple games, went to launch CoD:WaW. It installed directX, punkbuster, launched. My computer completely locked up, even ctrl/alt/del did nothing. I turned it off and on. Then I tried playing TF2, figuring, WaW is a crappily made game, it just crashed on its own. I launched TF2 and was met with a BSOD. I looked up the BSOD, it was graphics related.
I was really confused. I figured I had installed a bad driver.. so i rolled back to a previous version from the nVidia site.. and once I had done that, windows began to BSOD every 2 minutes or so. Then..I had my laptop on my bed, and I just kinda hit it with my fist... BSOD.
I booted windows back up, and I disabled the GTX560M in device manager. All the BSODs stopped. I can play any game, but with the ty integrated only. If I even use a program that barely has anything to do with the 560m (3dmark11 when it gathered hardware info, steam hardware survey, etc) I get an immediate BSOD. What is going on??? :/ Did I knock something loose? I used furmark at first and it worked fine, I remember getting 20+ fps with it, and that was definitely not my integrated card. Now, running furmark with an enabled 560m causes, of course, a BSOD. Do you guys have any idea how optimus works, how it's possible for all of this to happen? Should I open my laptop up again and search for some cord? I never opened the cooling block thing, so I don't understand how anything in it could have been messed up, unless it shook while being shipped, and I would not like to waste another 130 dollars for Toshiba not to help me at all. (Although I can't really blame them)
Thanks NBR, I don't know where else to go....

 

If the problem only started when you took the system apart, it seems likely that the disassembly caused the problem. You may benefit from opening it up again to check for disconnected wires or loose heatsinks.

If you don't want to do that, you can either send it back to Toshiba or get used to computing without dedicated graphics. If you have a BIOS option to only use integrated graphics, I'd enable it until you figure out the problem.