PC only posts after several attempts - sometimes CPU LED lit, sometimes VGA LED

[137qwayet]

Hi folks,

 

I recently build myself a new PC with the following components:

 

MB: ASUS B550-A Gaming

CPU: Ryzen 5800x

RAM: Corsair Dominator 4x8gb 3600Mhz

GPU: MSI Suprim RTX 3070

PSU: Corsair HX850

 

After building the PC and starting it for the first time I didn't get any display, just the red CPU led on the motherboard was lit.

I didn't think about it much and tried again. The PC then posted correctly so I could install windows, all the drivers, updates, etc.

 

Now everytime I want to turn PC on, it takes me several tries until the PC finally starts booting.

 

When I power it on, all fans start spinning and the RGB lights up but I don't get any display.

In this case the CPU led on the motherboard stays lit. Sometimes the CPU led then goes off and the VGA led is lit. But still no posting.

 

After several attempts the PC eventually boots up correctly. Everything then works fine as far as I can tell. I can use it normally, play games and so on.

 

I already did all the major updates (including BIOS), checked all the connectors, cleared CMOS, and cycled my RAMs, without any succes.

My next step would me to reseat the CPU and check for bent pins.

 

Also, my PSU (which is new) is making annoying coil whining / buzzing noises. Even when the PC is in idle.

So maybe that's the cause?

 

Any help is appreciated.