PC not turning ON after installing RAM

Hi to all,

I'm having a small problem. Recently, I purchased a new RAM, a 2GB DDR2 800MHz RAM (Forgot the manufacturer). I tried installing the RAM on my PC. So, I removed the case and put in the RAM and made sure it was tight. Then I tried turning the PC on. The system is already having a 2GB DDR2 RAM. But the problem is that the PC just wouldn't turn ON. I again removed the new RAM and installed it again and tightened it. Again tried turning it ON but nothing appears on the screen. There's power and all the things are turning on (except keyboard). My internal speakers are not working so I can't hear the beep sound too. But the fans are working and all the devices are turning on. I tried connecting the monitor cables and other cables outside the cabinet tightly but still, nothing would appear on the screen. I thought the RAM was faulty and I removed the new one and put back the case and turned it on. But even after removing the new RAM, the condition is the same. The PC wouldn't display anything on the monitor. I'm quite confused here. I don't know what exactly is the problem.

I need to know what may have caused the PC not to start and I need to know some ways to fix this. Please reply ASAP.

Does it start working if you remove the stick? If so it sounds like either a bad RAM slot, or the RAM itself is bad. Not sure of what else that could be.