ASUS Z170-A won't boot

Yep - same issue here. They would randomly come up depending on how long it stayed powered up.
I already sent mine back - will see what happens when it gets back. You mentioned that you RMAed the PSU as well - what brand/model is it?

You may be right - I might just be unlucky - I've called my retailer and they've offered a replacement or credit back. I decided to get a replacement - after all if it happens again I can always return it for credit next time.

Also - it's not ASUS that has offered the replacement - I contacted ASUS directly - and they basically told me - "contact your retailer", so no support from them, which I find a bit weird.

the PSU is a Rosewill ARC-750w. I am looking at replacing it will a more reliable brand just in case. Sent my i5 back to intel today for RMA cause thats the last big item that could be causing the issue.

That sounds like a good shout.
I haven't sent mine just because I hope that it's the mobo's fault.
If the problem persists with the new unit I will start RMAing all of them.

Let's hope that day doesn't come

Thank for the update, I was pretty certain the motherboard was bad. What I don't know is if I have memory or CPU issues beyond that. Everyone has been doing a great job at adding useful information, its appreciated.

I still have yet to replace my RAM but I tested it in another PC and it ran FINE.

That sounds more familier.
Their customer support doesnt seem the be that great.

That is honestly why I love gigabyte even in the US the customer service has been top notch for me. Hell I called them today about the issue and they helped me figure out that the mem controller in the CPU must have been killed when my PSU spiked and killed the last board.