Z2 mini G9 desktop workstation refuses to power on

[StelianGosu]

After just a couple of hours of normal use, our new Z2 mini G9 desktop workstation (5F0C7EA) refuses to power on being almost dead.

But not completely dead because one internal led blinks in yellow when the external power supply is connected
and then at about 10 seconds after, the front white led from the power on button blinks for less than a second too.

After that nothing happens and I mean no beep, no fan, no other led, just dead.

Things I have already tried:

a. swap the external power supply (including the power cord) with another one from an identical working Z2 mini G9

b. I tried the other way around and both power supplies are confirmed to be working with another Z2 mini G9

c. cmos reset by pressing the internal button and also by completely removing the battery

d. push the front power on button for 20 seconds or so

e. reseat the ram modules, ssd, video card and even the wireless module

f. disassembled the power on button in order to press directly

In the end I think the motherboard is at fault maybe due to a corrupt bios.

I would like to know if there is something else I can do, perhaps a special bios recovery procedure ?

I have to mention though that no peripheral works including keyboard or monitor and that the defective unit was protected at all times by an apc surge protector power strip.

I also tried to power on without any detachable component like video card, ram, ssd and so on but the issue remained:
one internal yellow blink at power supply connect, followed by a very short white blink at the front power on button then nothing.

[VampireCJ]

For troubleshooting on this device with the issue you are experiencing, please try the following and let us know of the results.

1. Hard Reset - Make sure everything is unplugged (Power, Keyboard/mouse, Monitors, Ethernet) and then hold down the power button for a least 30 seconds. Then plug in the bare minimum to use the unit (Power, Keyboard, Monitor) and try to turn on the unit.

2. BIOS Recovery - On this unit, the BIOS Recovery step is to double tap the power button in quick clicks (Within 2 seconds).

3. CMOS Reset - I know you said in the post that you did this one, but I just wanna make sure the step is followed correctly. Unplug "everything" again and then hold down the CMOS Reset button for at least 5 seconds or remove the CMOS Battery and hold the power button down for at least 5 seconds.

If those steps didn't work and because the G9 series is still new to the point of it still being under warranty, I would contact HP Workstation Support at 800-334-5144 and let them know what is going on. They will ask what troubleshooting steps you have already preformed for this and you can state what you did as well as what I have listed here and how they were done. They may have like maybe one more step after that, but you can probably get this set up for a new system board through service at that point.

[StelianGosu]

Thank you for the additional troubleshooting steps

but unfortunately none of them worked in my case:

1. hard reset
2. bios recovery (double tap)
3. cmos reset

The issue remained:
just one internal yellow blink when connecting the external power supply
then after about 10 seconds a very short white blink at the front power on button
then nothing happens (no beep, no fan, no lights)

The unit was only used for a couple of hours

mainly to test the pxe boot process from a mdt/wds server

after injecting the missing drivers (network and irst) into winpe image

the mdt boot task sequence succeeded

then a more recent network driver was added in windows 11 pro to enable wake from lan (wol)

and after that the unit was powered off to test wol which worked perfectly

with some additional settings like disabling the fast boot and so on

at the end of the working day the unit was shutdown and remained like that during the weekend

and next week when I tried to power on the unit in order to create a reference image

I noticed it was not working and then check the cables and start the troubleshooting steps

Unfortunately none of the troubleshooting steps (a-f and 1-3) worked in my case.