I decided to add some ram to my old pc, because 2x1gb wasn't really enough. So i replaced one of the 1gb ram stick with 2gb ram stick. And here the problems begin: first of all i saw on screen something about "BIOS recovery", also it printed a lot of dots. I decided to turn it off, so i held off button for about 4secs. After that i tried to turn it on, but if usually i hear a beep, and after that computer shows everything else on screen, then this time i didn't hear beep and screen was black all the time too. I waited for a minute, but nothing changed. So i placed back old 1gb ram stick, but computer still don't boot. Black screen and no beeps. What happened? Did i break something? Please, help me with advice