First of all, the system isn't going to POST if you changed that jumper setting. It must be in the "non-cleared" position. If you moved it, to clear the BIOS, move it back. Some system will POST with the jumper in the clear position, but its not supposed to be run in that position anyways.
Second, double check all your connections. Make sure everything is still plugged in good and solid. Reseat your RAM and make sure it had a good connection. There are some instructions here that covers reseating the RAM near the end of the article: http://forums.whatth...ms_t103823.html
If the problem occured after you poked your fingers inside the case you can bet that the problem is related to something you poked.
