Black screen

Motherboard-MS7255 v 1.2 I won’t say about BIOS, I don’t know. BP-
Proc.-Core2 Duo E6420 Memory-KVR667D2N51G There was no overclocking. Guys, hello everyone. The problem is this, the motherboard turns on, but does not start (the coolers are spinning, the speaker is silent, the monitor is black). I got the computer by chance, so I don’t know everything. It was like this. The first time it was launched before the Windows 7 logo. I went into reboot. Without turning off the computer (on the go), I changed F, D. The computer hung, I had to turn it off forcibly. What I tried to do. First of all, I checked everything visually, everything looked fine, reset the BIOS (with a battery and a jumper), changed the power supply, now I pulled the motherboard out of the case, tried to start it up, nothing happened. Yes, I took out the video card, took out the plank. With them, without them, the effect is 0.