Question PC power issue, never seen before..

Apr 20, 2020
1
0
10
Have a strange one here.... Been building comps for log time and never come across this.

So on an old desktop, functioning till recently, build (i7 2600k - Asrock Z68 Extreme7 Gen3 - ripjaw Z DDR3 2133) I seem to be having a power issue. That is, when the plug is switched on from the wall socket, it takes about 15 mins for the system to gain enough power to light up internal GPU lights and peripherals. During this time the power button is dead and all lights( RGB fans, mouse GPU) are off as if no power supplied. Having watched for a the whole laborious 15 mins, it is note mentioning that the mouse(which usually pulses), flickers in dull fashion and looked as if struggling to get power to operate correctly when nearing the 15 min mark.

Have checked PSU by green/black jump, runs as should and instant. Changed cms battery. My thoughts are with the mobo on way out... Has any one else experienced and resolved an issue same in nature or offer insight into probable cause?