I recently started having some computer problems.
Basically, I switch it on. it powers up, fans spinning, hard disk spinning.
But on the screen, black. not even BIOS, POST or whatever the first things appearing on the screen are.
Usually after many tries it actually manages to start up properly, but I haven't managed to find any common fact between those successful attempts.
I tried changing the screen, changing the power socket the computer is attached to, changing the video cable, removing GPU and linking video cable directly to motherboard, moved RAM, cleaned connectors and nothing helps. It is not overheating, I checked temperature when I managed to switch it on, but it was quite cool. This problem happens only at startup, after that computer runs fine.
motherboard gives no beeps. Like, at all. I suspect the speaker is not installed.
What should I do? I was thinking about resetting the BIOS , but this is starting to reach uncharted territory for me. it seems dangerous.
Last time the computer refused to switch on like this it was because I had linked power spply to CPU fan but not CPU itself. the intermittent nature of this problem and the fact it works fine after startup seems to rule out processor problems , in my ignorant opinion. But still, any safe way to check if CPU is running?
Any idea on possible causes and possible fixes?