Mobo issues

[Avic4]

Hello all,
I hope this is the right place to post this if not please refer me.
I have an old Z68X-UD5-B3.
Lately it's developed a problem. When it's hot it won't turn on. If I leave it for about an hour sometimes more it turns on. I can leave it on for days no problem but after I turn off the computer if I try turning it on again it's hopeless. I need to wait. Can anyone help narrow down what might be the malfunction?
Thanks in advance.

[shadowsports]

Greetings,

Z68X-UD5-B3..  great board with B3 chipset revision in its day.  I ran mine with a SandyBridge, then IvyBridge processor for years.

You're at the 10 yr point. 

What you can try, in no specific order:

-CLR_CMOS / Reset its BIOS and configure from scratch
-Inspect the chips, capacitors and IC's for bulging, discoloration or visible signs of heat damage
-Try a different PSU (if this is as old as the board, it can fail too)

-My advice, don't invest further in this now obsolete technology.  Any future dollars should be spent on current tech.

Good Luck! 

[Avic4]

Thanks friend. I will try your suggestions.
Still using 2600k on mine and it is 10yo.