I am fighting an odd issue in one of my Z400s.

It turns itself off periodically and the beep code indicates "power failure" -- four beeps.

First time I have seen this and it NOT be a power supply (changed PSU already).

So I removed two out of three 1070Ti cards -- running it on just one for at least 24 hours to see if the issues persists. Then I will add cards back one at a time if it does NOT persist on the single card.

I also re-pasted the chipset heat-sink as that seemed to be running a bit hot (just in case).

If all else fails it may be my first case of actual Z400 hardware failing (maybe motherboard).