Info about GA-586ATM mainboard

I want to install an Intel P 133 CPU on a GA-586ATM board. My configuration is: JP6: 1-2 close, 3-4 open
JP4,5:both 2-3
2 4-MB simms installed at SIMM 1 and SIMM 2 (Maybe they interfere with the motherboard, they're from a 486 machine?)
When I try to boot I only get a black screen and no beeps. There's obviously no POST
What is the big connector between the CPU-slot and the PCI/ISA sockets?
On my board there are 2 jumpers connecting pins 6-7 and 6-7 from the right
A mainbord manual in PDF-format would also help.