Question My PC turns on but keyboard/mouse doesn't work and it gives me a black screen

[zWaster]

Hi guys, so, I've been having this issue with my PC for a long time but Idk what causes this. I turn it on, all lights/fans works but I only see a black screen ( no peripherals works either). I know the GPU is fine because my monitor shows that something is connected to it, so the monitor recognizes that the GPU is there ( I don't receive any error message on the screen btw). After a few tries I could "fix" the problem but it keeps coming back. What is weird is that the solutions are completely random. Sometimes I just need to take a random RAM out(I have 3x4GB ) turn on the PC and it works just fine, than I put the same RAM back in and everything works again ( it doesn't matter which one I remove, it works again ) . Sometimes I need to take the GPU out, turn everything on ... it works ... than I stick the same GPU back and guess what ? PC works as if nothing had happened ! I can oftenly fix the trouble and put the PC to work but I have no freaking idea what is causing this. My guess is that something is wrong with the motherboard but I'm not sure. Do you guys have any idea what is causing this ? Is there anything I can do to try to permanent fix this ?

 

[rgd1101]

full system spec? include make and model of the psu

 

[zWaster]

Asus B85M-E/BR
Intel I5 4460
MSI GTX 1070 Gaming X
3x 4GB Hyper X 1600 mHz
Cooler Master G500 500W 80 + Bronze

 

[JustAnOverclocker]

Asus B85M-E/BR
Intel I5 4460
MSI GTX 1070 Gaming X
3x 4GB Hyper X 1600 mHz
Cooler Master G500 500W 80 + Bronze

In reading your original post, I was thinking "motherboard." THE USB ports are obviously connected there, along with everything else, so it is the common denominator among all of them.

Then I saw you had a 500W power supply.

Here's the thing: The signal to noise ratio degrades the CLOSER your total system draw gets to the PSU rating. So if you're pulling 430W on a 500W supply you're going to eventually spawn a signal with more noise than if you had a 1000W supply under the same load. And guess what? Lousy signal-to-noise ratios manifest themselves as RANDOM errors in multiple devices! And that sounds like your issue if I had to guess.

Since the PSU is so easy to swap out, see if you can "buddy buddy" someone on GeekSquad into doing a quick test for $25 before you go out and dump money on a higher-end PSU. If you get the same errors with the new high-wattage PSU, then it looks like the motherboard. But, if this stabilizes everything, you know what it is.

 

[zWaster]

Ok, I'll try to get this PSU tested though