pc wont boot up

When I turn on the main switch, the RGB lights on my GPU and case fans light up before I press the start button on the case. After I press the button, nothing happens, the lights on my keyboard and mouse don’t start and there is no video output to the monitor. I also don’t hear the soft beep...

Hello, I'm trying to upgrade my grandparent's PC with some new ram. Their Mobo is an MSI 2A9C, they currently have 1x1gb and 1x2gb ram sticks in there, and I've tryed to replace it with 2x4gb. I saw on Speccy that it sais their ram's max. bandwith is PC3 - 10700 (667MHz) DDR3 (And I don't know...

So basically, I got a new case the Core P3 Snow White and transferred all my old parts to the new case. In the old case, there were no problems with it but now it wont consistently boot and I have to trail and error until it boots. I feel like I’m missing something obvious or something else went...

Build- gateway lx6810 Everything stock but Nvidia GeForce 710 gpu, and 400w evga psu. Computer turns on but will not display anything LEDs turn on all fans turn on, I can hear the hard drive startup but no post beep, and the power button is usually a solid blue now when it turns on it blinks...