what did I do?

[gaveupontv]

I have a first gen i7  2.9 mhz with a Asus sabretooth mb. I am fairly experienced but I haven't had this incident before. I was considering buying this computer moniter but it wouldn't work. Now that I think about it, it didn't work in the same way my computer doesn't work now it didn't have a wall plug with 110 but you plugged in this voltage reducer that went to the wall and voltage was  dropped to 17 volts or maybe it was 17 watts anyway it was the only adapter that met the specs written on the back of the Samsung moniter like I said it didn't have a normal female plug in that usual plug and didn't use those short power cables that go in power supplies, moniters etc. So the new moniter just had a pattern it said to check the cable it wasn't getting a signal and nothing I could do, like switching cables would get the moniter working. Then while I was putting everything back together I accidently bumped the cord and pulled it out from the back of the video card at a angle it came out easily it wasn't screwed in and somewhere after that I couldn't get my desktop to either of the 2 moniters that I use. So either that new non working moniter did something to my computer or when I pulled out the video cable it did something. Everything was running while I was switching moniters around, I ve always done it that way and I ve never had the slightest problem with that plugging and unplugging moniters while windows10 (or any os) was running. I don't get a post screen while its booting the only thing it could be IMO would be video card (cant think what else it could be) its not cables or moniters. Is there anything else i could try before buying another video card?
When I bought the computer it has sli, but I let it get too hot (left cover off and it fried one of the gx460 cards) so I'm down to one card now I would hate to buy a card and have the same thing. I guess it could be the motherboard too Thanks for any help!

[patio]

You have been pluggin/unpluggin monitors and kickin cables...all with the power on...your lucky the PC even boots.

[gaveupontv]

Actually it doesn't boot, that is what my post is about. How would it be harmful unplugging the moniter?.  I can understand with something carrying power but its just a signal. There are a bunch of places/actions that wouldn't be advisiable, IMO that isn't one of them.
I guess you don't have a guess.? I must have hit you on a bad day

[BC_Programmer]

Have you reseated the Video card? Even if you screwed in the video card (which seems to be counter indicated by not bothering to do so with the cable, in a sense) it can still loosen the graphics card, so it is worth reseating it.

You should be able to determine if the graphics card is the culprit by either installing a known-good graphics card or trying that graphics card in a working system and seeing if it Posts.

How would it be harmful unplugging the moniter?.  I can understand with something carrying power but its just a signal.

Signals/data connections use electricity to work, so it is already powered. DVI also has a 5V power pin.

[gaveupontv]

Well, it's working again. I ended up removing and replacing the video card 3 times. Cleaned it up (dust)  and it did nothing, no post, nothing. So I tried an older PCI card and it did the same thing. I didn't do anything for a day or two, came back with another old card, it posted, and the bios had to be re-configured and it couldn't find the right hard drive until I disconnected a couple of them (I have 4). So everything was back up with crappy resolution. I thought about it and figured I'd try my original video card again and sure enough it was working. I'm back in business!
All I did was put different video cards and cleaned everything, altho it was dusted not too long ago.
Maybe I won't be changing monitors when I'm up on Windows anymore. Windows 10 boots pretty fast anyway, it not like I'm losing 5 minutes for a long reboot.
Thanks for the help!