What cause a computer to turn on but powers itself down and will not log on but

[Good old newfie]

Hello, I have a Gateway computer that will power on but do not shut down and will not show anything on the screen but when i turns it on it sound like it strat to go and the power all slow down and stay on. Thank for any help. good old newfie.

 

[T_T]

Here are some things for you to check:

1. Try a different signal cable (Blue or White connectors) between monitor and computer
2. Power down the system. Open the case, and then remove your RAM. Turn on. If you hear beeps, then it's possible one or more of your RAM sticks went bad.
3. The power supply could be going bad, use a different PSU of like quality (or better).