Question Pc turns on but no display or keyboard or mouse

[Dankpepe5000]

So i bought a used 2060 and put in some case fans , everything worked fine , updated drivers and stuff and the next morning when i tried to turn it on , it did start but with a black screen (no signal) and keyboard and mouse wasnt working aswell , i tried reseting the rams , reseting cmos battery and it cant be a PSU fault because i bought it like 3 months ago brand new.
Could anybody help me fix this?
Specs:
Os:windows 10
Cpu:i5-4460
Mobo:Asrock h87m pro4
Gpu:Zotac 2060rtx
Ram:24gb
Ssd:kingston 128gb
Hdd:toshiba 1tb

Ps: i plan to buy a new cpu mobo and ram if its a lost cause , but please help asap

 

[stonecarver]

Might or might not help you. I just had a clients weird computer do the same thing.

Brought it to me and sure enough it booted right up on my test bench. I didn't charge him, he took home and black screen ? Brought back and it booted no issue.

I had him bring me everything. Monitor, mouse, keyboard.

It turned out the way to get him to boot was as he boots just click any random keys on keyboard.
I also had him turn off and on his monitor.

It seemed his BIOS thought there was no keyboard/ monitor and hung there.

I didn't charge him in the end as I fixed nothing but he is now working.

 

[Dankpepe5000]

Might or might not help you. I just had a clients weird computer do the same thing.

Brought it to me and sure enough it booted right up on my test bench. I didn't charge him, he took home and black screen ? Brought back and it booted no issue.

I had him bring me everything. Monitor, mouse, keyboard.

It turned out the way to get him to boot was as he boots just click any random keys on keyboard.
I also had him turn off and on his monitor.

It seemed his BIOS thought there was no keyboard/ monitor and hung there.

I didn't charge him in the end as I fixed nothing but he is now working.

I tried to press random keys but didnt work , since the keyboard isnt lit up i suppose it isnt getting any power same as the mouse , for the monitors both say no signal.
Cant figure out what is wrong with it because it shouldnt turn on and off itself 3 times , like there is a error in POST