Z620 power button in constant red state

[DaveM54]

I have an HP Z620 workstation (dual E5-2650 CPUs, 64Gb RAM, Windows 10) on which the Power Button is constantly red. The system does not display any BIOS/POST errors and will boot to Windows 10 but sometimes completely powers off. Generally the fans are silent but the sometimes become very noisy. I have read through the maintenance guide but cannot find anyway to get a meaniful diagnostic message/error code to point me in the direction of the fault. I suspect it maybe a power supply fault but would like something more certain/a second opinion before starting to replace components on spec. From the manual I would have expected the power light to be flashing and the system beeping to indicate the cause of the fault. What am I missing?

[itsmyname]

@DaveM54 -- From the manual I would have expected the power light to be flashing and the system beeping to indicate the cause of the fault. 

That is correct, if the computer is powered-on, and the initial "POST" ("Power On Self Test") detects a hardware problem.

However, given that Windows does successfully & completely load, and then crashes, you have some problem that the POST did not detect.  It could be "overheating" -- if any of the fans inside the power-supply and/or case have failed -- that is forcing the power-off.

[DaveM54]

Thanks for the feedback. I have moved forward and (1) removed the 2nd CPU riser board and reseated the 1st CPU and fitted a Z640 heatsink to this CPU. The system is now back running reliably (I'm tempting fate here!) and totally silently. The only irritation is that the power light is still showing red. Is there any way to reset this?