Gateway GT5228 PC Desktop "again rhyme" Questions

...Again no seeming rhyme or reason. Even checked for rootkits on computer none found. Power supply changeout was same result. Hard disk is noisy but o.k. for now. Would like to know how to get the ...

...again." The power light glows amber, the fan powers up high for five seconds, shuts off for five, up for five, off for five, literally for hours. Unplugging everything, even power, for one minute, 5 ...

rhyme or reason to when it would start. I could leave it sit for an hour or I could keep trying to turn it off and then on again. I have eliminated the power supply as I installed another (larger) PSU

...again by having your finger on the f8 ready to start pressing) if you did at the right time you will see a black screen titled advance startup options, with the arrow keys select safe mode and press ...