HP Z620: full speed fan and no display

[VERNIERAntoine]

Hello !

Since my move, I have encountered a problem with my HP Z620 Workstation (2 Intel Xeon E5-2650, 192 GB of RDDR3 ECC RAM, NVIDIA NVS315, 2 SSD, 4 HDD).

Almost randomly, it starts, does not display anything on the screen and the fans run at full speed

I tested by removing non-essential components:

• network card (4 GigaEthernet ports),
• PCI card (2 console ports),
• second processor and its memory,
• the 3 hard drives in the bay

I took the opportunity to do a memory test. The memory test reported nothing, at least for the first processor.

I did an almost complete disassembly: graphics card, storage (SSD and HDD), memory, second processor, power supply.

I failed to remove: the right side panel, the motherboard and the front fans.

Do you have a solution?

[Brian1965]

Hi and welcome to the forum.

EDIT - Sorry, I may have mis-read your post. Are you saying that your computer is working normally, but when you shut the computer down, it is restarting all by itself?

'Since my move' - Could this be a simple motherboard battery issue not retaining your previous settings, or corrupting your BIOS? It sounds like you may have had the system unplugged for at least a few hours - more than enough for the capacitors and PSU to drain any residual power.

I would first try and simply replace your motherboard battery. After replacing the battery, remove the power lead from the computer and press the power button at least 4 or 5 times to discharge any capacitors and the PSU. Then press and hold the CMOS reset button for at least five seconds.

Plug the computer back in and power on the system. The system fans may spin up for a bit when first powered on and you may not see any display as yet. Normally, after about 30 seconds or so the system should reboot, (without the fans spinning full speed), and you should hopefully see the BIOS POST messages. Press F10 to modify and save your BIOS settings.

If the above doesn't work, then you may have to perform a BIOS Crisis Recovery. This procedure has been fully explained in a post by SDH.

[VERNIERAntoine]

Hello and thank you for your return,

Since my move in late July / early August 2019, the workstation has been transported and stored. I took it back in February 2020.

I think I have already changed the CMOS battery. As I have no more in reserve, I will buy it again and try again.

I have already tried to unplug the power cable and hold the power button for up to 10 seconds. I am used to this approach.

I pressed 5 to 10 seconds on the CMOS reset button, I plug in the power cable, the workstation starts automatically for 1 minute with the fans at low speed.

The workstation turns off and restarts, after a few seconds / minutes, the fans run at full speed.

Lastly, I will look at the procedure for BIOS crisis recovery

[Brian1965]

IMPORTANT -  If the motherboard CMOS battery is dead, (or nearly dead), then pressing the Clear CMOS button won't make any difference. It sounds like the system is trying to read your motherboard hardware ID's, bus speeds, etc. at the first boot, but can't save the changes. Since the computer has been in storage, (and not plugged in to a mains socket), the CMOS battery will drain significantly faster than normal. If you haven't changed the battery this year, then I would definitely replace it first.

I assume your are not seeing any POST display and the computer is not indicating any BIOS errors, i.e. beeps or Power LED flashing?

[VERNIERAntoine]

Exactly,

There is no POST display, There are no beeps or blinking power light.

The power button is solid blue.

[Brian1965]

Please make sure you only buy a quality branded battery, e.g. Energizer, Duracell, etc. and not those cheap unbranded multi-packs you get for a $1/£1 in the local 'bargain' store. I definitely would not attempt any Crisis Recovery, (if needed), until you replace the motherboard battery. (type CR2032).

Post back once you get the battery replaced.

[VERNIERAntoine]

What to do when the plastic holding the CMOS battery does not support (break) during the replacement of the CMOS battery?

The support is really crappy

[Brian1965]

Oops. That definitely didn't quite go to plan. I'm guessing you have 3 possible options to try to salvage your Z620, unfortunately, the first 2 options require a soldering iron, a steady hand, and hopefully some soldering experience. Not a job for the soldering novice. Alternatively, you may know someone or somewhere that can repair the motherboard for you.

Option 1 - Buy a replacement CR2032 battery holder and replace the damaged battery holder. (About £8 for a pack of 10 on Amazon). You would need to remove the motherboard to complete the repair.

Option 2 - Buy a laptop replacement CR2032 battery - these are also readily available on Amazon. The battery is encased in a plastic sleeve and is connected to the motherboard via a red and black wire terminating in a small connector. It should be possible to remove the small connector and solder the leads directly to the motherboard, without the need to remove the motherboard. It also means you don't need to de-solder and remove the damaged battery holder - the high risk part of the repair, i.e. soldering is easy, de-soldering can be tricky and risks damaging the copper traces on the PCB due to excessive and prolonged heating.

Option 3 - The expensive option - replace the motherboard. Not ideal, but replacement HP Z620 motherboards are available on ebay. If you do decide to go this route, then make sure you get a v2 motherboard, (2013 boot block date).

[VERNIERAntoine]

Yes, ...

I traded with another computer technician and we agree on this point, these types of cmos battery outlet is really crappy.

I will consider a change of the cmos battery socket. I have a soldering iron.

However, the removal of the motherboard does not seem clear to me, I understood that there is a joystick to rotate and after ...

I also had the idea of an adhesive or a piece of paper, cardboard or plastic to wedge the battery in the socket

[Brian1965]

It might be worth while just trying the adhesive tape/paper technique to confirm that the motherboard is okay before attempting the full repair. i.e. if the tape/paper works then don't leave the Z620 motherboard in this state as no doubt the temporary repair will likely fail at some point - when you least expect it, or when you're doing something important on the system.