Problem -PSU/MoBo

[PawelPawlak]

Hello.

For almost 4 years I had i7-2600K@4Ghz cooled with Corsair H100
running on Gigabyte Z68XP-UD4.
All powered by Thermaltake Toughpower Grand PSU.
System was running almost 24/7 - no problems.
Once my DVD has stopped to work, so I turned off PC, installed new DVD.
When I tried to turn on PC it was like power button did`nt work.
Card reader LED in my case was lit (when PSU on), but even PSU fan did not start when
trying to switch on.
Components were checked (in 3 different computer repair places) and repair guys said that motherboard is faulty, but no1 could say what is exectly wrong with it.
I have bought new motherboard (that problably was not so new) - Asus Sabertooth Z77.
Probably not so new cause box was already earlier opened, optional motherboard fans were installed and some wear signs.
After intallation there were problems from the beginning. It was hard to start PC after turning off and on PSU. Sometimes I had to press power button like 20 times until system went on. With PSU not earlier turned off/on - there were no problems with starting with power button.
Other problem was that BIOS setting were lost after turning PSU off (strangely profiles saved in BIOS - were not lost then). I changed motherboard battery to new one - it did`nt help.
One last information - sometimes - like 1 in 20 - when I turn on PSU - for 2 seconds my UPS goes on (like when during power outage) - is this normal?

Can anyone say if maybe my PSU is faulty and causes problems motherboard problems?
Or maybe it`s just my bad luck with bad motherboards?

 

[Tsumi]

Best way to find out is to put the PSU in a different known working system, or put a different known working PSU in your system. Unfortunately, this is one of those things that can only be troubleshot by swapping components.