HP-Z620 Shuts Down On Its Own and Power Button Flashes Red

[PeterKH]

HP-Z620 shuts down on Its own and Power Button blinks in red. I have had large files to download--approx. 70+ hours to download them all.  The Z620 keeps shutting down and when I notice it the power button/start up button is flashing red. When I press the Power Button it turns blue and Windows 10 and the Z620 start up normally with no error messages from Windows 10 at the startup.

Could any give me any solutions. One approach would be to download some HP Hardware analysis utility that could check if the PC is overheating, so if fans are working OK or whatever.

Any suggestions are welcomed. My computer is old so I am not entitled to any detailed support from HP without paying fees.

[SDH]

There is a downloadable Service Guide at this address, and this is version 5:

http://h10032.www1.hp.com/ctg/Manual/c04205252

On pages 145-147 the blink codes are described.  In my experience you likely have a power supply going bad.  There is just one power supply for the Z620.... some other workstations have two, one regular and one for high wattage configurations.  The Z620 power supply is very easy to unplug and replace, with many available used off eBay.  I'd not hesitate to buy a used one.... and have.  Go to eBay and search for "Z620 power supply" and you can sort by price + shipping lowest.... and find them there for as little as 30.00 USD .  I'd buy only from a US well rated eBay seller.  These come from Z620s that are being parted out after retirement.

It could be something else, of course, and the "beep/blink codes" should help you narrow things down.  Sounds intermittent, and those can be hard to figure out.

Best of luck to you on your project!

[Brian1965]

It could also be a simple over-heating issue, quite common on older computer systems, (unless you live in a temperature and humidity controlled cleanroom). The first thing I would do is open the side door and inspect the inside for any accumulation of dust. It doesn't just restrict the airflow across the heatsinks, dust is also a great thermal insulator. A 1 inch paint brush and a can of compressed air (Amazon, eBay, etc.) can work wonders. The older Quadro graphics card can be prone to getting pretty dirty, causing the computer to shutdown without any pre-warning. I had an old Quadro K4000 card that had this issue, and a friend had a similar issue issue with a K4200 card. A good clean and the problem was gone.

You could also download and install OpenHardwareMonitor to view your CPU, GPU and SSD/HDD drives temperatures in realtime. If you go to the View/Show Plot option in the drop-down menu, you can easily monitor for any temperature trends. If all the temps look fine, then I would look to re-seating any internal connectors, DIMMS, or PCI cards, etc.

[PeterKH]

Thanks SDH and Brian for your suggstions and help. Now the problem is worse. The HP-Z620 won't open up Windows 10 and it just has racing and loud fans.

[Brian1965]

Did you get a chance to run the BIST (Built-In Self-Test) on the PSU? Disconnect the PSU power from the Z620 motherboard, then switch on the PSU. The fan in the PSU should spin up and a solid green LED should illuminate. You will need to view the PSU from the rear of the Z620 to see the LED.

Another possible cause could be an issue with the system ambient temperature sensor which has been known to fail. This is a thermistor located in the Z620 power button harness assembly. I have read of at least 2 forum members having this problem. 

I may have missed it, but did you count the number of red flashes you were getting, (as mentioned in your original post)?