PSU starting to fail?

xzeve84

Prominent
Feb 3, 2018
6
0
510
first of all - when my pc is turned on there are no problems- it runs smooth for hours and hours without any issues even at full load.

The problem is, when its shut down, and i want to turn it on.
All my fans starts up, i hear my HDD and all is as it should be - except my keyboard + mouse dosnt power on, and my screen says "no signal". nothing changes if i leave it like that for several minuts, and i turn in back off.
sometimes i have to "turn it on" 5-10 times before i have any succes, and other times it works instantly.

As i said, no problems when its actually running.
i have tried resetting CMOS , set everything i BIOS to default, disconnected everything 1 by 1, except with my PSU since i dont have a spare one of those to test with.

My PSU is 5+ years old, and i kind of starts thinking that it is the problem.
but would that lead to such random power errors , and only at boot?
 
i5-4460 (3.2ghz) some Asus basic motherboard , 8 GB ram and a cheap gtx750ti - and a SSD for my OS and a storage HDD.
Nothing fancy, but it fits my pc needs... :)
 
it turned out (after mounting a speaker ) that its my pciexpress port that causes the problem at powerup. using asus motherboard, and it beeped "long-short-shor-short"
i have tryed to mount 2 other gfx cards , and get the error code at both of them as well.