Some time when you press the computer power button, the computer may be on but screen does not display anything. Why this problem is arise and how can we solve this issues, is to say here.
RAM is usually due to a problem. RAM clear and open, and it will put the good motherboard slot. If this problem can be solved.
The problem may be due to the power monitor connection. So you can see the change in electrical connection of the power. Check the monitor's VGA cable. Sometimes this can be a problem if the cable is not properly mounted.
Problem with the graphics card
Graphics card can be a problem, so an external graphics card placed Check.
The resolution also shows a lot of black monitor. So the monitor and PC graphics card can check the compatibility resolutions. Go directly to the computer's BIOS or VGA graphics card, you can change the options.