Screen starts flickering ,USB Keyboard and Mouse starts reconnecting

[AnOrdinaryPotato]

I am struggling with my old Core2Duo computer Keyboard and Mouse starts reconnecting just after few minutes of using it just then screen starts to flicker a bit.

Even after restarting it immediately it doesn't works ... Crazy thing is after restarting keyboard doesn't even work in bios menu.. after leaving it for an hour or so it seems to work again for a few minutes then crashes again the system is not hanged or something problem is with just keyboard and mouse.

 

I thought something is wrong with the keyboard so I bought new  Hp C2500 keyboard and mouse they are working on my laptop perfectly but the issue is same with my old computer

[KarathKasun]

Sounds like the laptop has had it, unless you want to disassemble the laptop and diagnose the power circuitry on the logic board.

[AnOrdinaryPotato]

35 minutes ago, KarathKasun said:

Sounds like the laptop has had it, unless you want to disassemble the laptop and diagnose the power circuitry on the logic board.

Sorry perhaps I didn't explain it properly , The problem is with my Core2Duo desktop computer running windows 7 

[KarathKasun]

7 minutes ago, AnOrdinaryPotato said:

Sorry perhaps I didn't explain it properly , The problem is with my Core2Duo desktop computer running windows 7 

Replace the PSU if its a desktop.  Sounds like the 5v rail is way too low.

[AnOrdinaryPotato]

On 02/09/2018 at 5:17 PM, KarathKasun said:

Replace the PSU if its a desktop.  Sounds like the 5v rail is way too low.

I tried replacing PSU but in the process I suddenly got shock from my VGA cable when I was detaching it from CPU ,

I got positive test light on metal end of VGA cable When I checked it using tester ,

 

Out of curiosity I replaced the monitor and everything is working fine for now.

But is it usual for VGA cable to carry electricity? And is the monitor repairable ?

[KarathKasun]

You may have a bad ground connection in the electrical outlet.  Some power supplies (in general, those for monitors or stereos too) need a physical ground or they will shock you if you touch any "grounding" metal on them.