[SOLVED] HP Z640 Workstation "Pre-Video Graphic Card error"

SparkyTech934

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Jan 22, 2020
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Hello. I just bought a used HP Z640, and was in the initial stages of setting the device up at my home. I started by clearing the CMOS, and reverting any changes by the previous owner of the device in the firmware so I could set things up how I wanted them. I noticed that legacy support was enabled, and secure boot was disabled, so I changed the BIOS setting and set it to 'disable legacy support, enable secure boot' becuse I was going to install windows 10 (which of course has built in secure boot support).

Changing that BIOS setting is where my problem began. As of now, the machine will not POST becuase it doesn't like the vBIOS of the GPU (a GTX 660). The POST error code is red LED, 6 beeps, and 2 second wait.

Basically, my predicament is that now that the computer won't even get past the POST, I am unable to even enter the BIOS and revert to 'enable legacy support and disable secure boot' to get back to where it was working previously.

I have tried the following:
  • Clearing CMOS to revert settings (both with CMOS button, and by taking the battery out for 15 or so minutes). This did not work, I assume because clearing CMOS does not affect UEFI/Secure boot settings.
  • Taking GPU out of the machine, and reseating it. (obviously was a long shot, but was worth a try).
I am at a loss, and need some help with this. I'm a software developer and have plenty of hardware experience, but I feel like I kind of am stuck in a corner here, with not being able to even get into the machine's BIOS. I was thinking that I could try and get my hands on a newer GPU with UEFI support, but even then, there is only a 6-pin PCIe cable in the Z640, and most modern cards require an 8-pin connector. I'm honestly shocked that a simple firmware setting change could render the device so useless. That being said, I have a plan of a few workarounds, listed below..

  1. Use a second power supply to power a newer, UEFI capable GPU to get back into the BIOS and change the setting back
  2. Try and use the failover BootBlock mode to re-flash the BIOS from a USB drive. This option will most likey be uneffective due to the fact that it only allows a re-flash if it detects corruption which I do not think is the case here.
Related:
Service manual for the machine (mine is the Z640) - http://h10032.www1.hp.com/ctg/Manual/c04823811.pdf

Please post any suggestions, I appreciate your time and effort! I will update again if I find a solution.
 

SparkyTech934

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Jan 22, 2020
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Alright, so I was able to remedy the issue. I tried a few things, and since there was no video output, I'm not 100% sure exactly what the fix was, but I have a hunch, and will explain in summary. My order of operations is below:
  1. Removed all unneccesary components from the machine (this would be the setup I used for the rest of the troubleshooting). This included:
    1. Optional CPU board + RAM that was installed on it
    2. Wireless card
  2. Took out CMOS battery, waited more than 30 minutes
  3. Simultaneously to clearing CMOS, removed the GTX 660 (the original card that was being rejected by the BIOS), and replaced it, in the same slot (top slot) with a low profile video card.
  4. Replaced the CMOS battery, booted the machine
At this point, the video card error 6 beeps, accompanied by red LED, 2 second pause came back. No success. I continued below
  1. Moved the jumper on the BBR (Boot Block Recovery) header, shorting the pins towards the rear of the case.
  2. On another computer, created a flash drive image with the HP software on the Z640 support site. (extracted files and then followed prompts to make 'recovery drive'). Then plugged the USB drive into the back of the machine
  3. cleared CMOS again (CMOS button on board this time)
  4. Booted the machine into BBR mode. 8 beeps, accompanied by red LED (normal activity for BBR mode). The flash drive began pulsing/flashing before staying lit constantly. Eventually (after a few minutes), the machine's fans ramped up to 100% speed.
    1. NOTE: At this point, with the observed behavior, it did not appear to be doing what it should in BBR mode. All documentation regarding this mode say that if successful, the machine would boot twice and then shut down. I am unsure if BBR + USB recovery fixed anything.
  5. I force powered-off machine since it was in error state
  6. Replaced the jumper back to original pin location.
  7. Started the machine again (now in normal boot mode). 6 beeps, accompanied by red LED, 2 second pause persisted.
With trying BBR mode without any knowledge of of success/failure, and clearing CMOS still having no effect, I was begining to feel like this was going nowhere. My last attempt is detailed below:
  1. Cleared CMOS again (CMOS button on board)
  2. Switched out video card for another low-profile option that I had laying around (this one identified as a Geforce 210 GPU by Gigabyte, revision 6.0)
  3. Booted machine.
  4. Success! I saw an HP splash screen, and was able to access the BIOS after one more CMOS reset.
After getting to this point, I did the following, and I would highly recommend others do the same:
  1. Upgraded BIOS manually to the latest version (HP Z640 - version 2.57 as of May 2021)
  2. Set BIOS to factory defaults after upgrade.
  3. Put in the rest of the hardware.
  4. Tried another GPU (RTX 2060) and changed the original setting that messed me up
    1. 'disable legacy support, enable secure boot'
  5. Everything still worked fine after that.
Summary
Alright, so to summarize and play some detective work, I believe that the fix was as simple as replacing the video card with another unit that the system was able to interface with in UEFI only mode. I would like to think that using BBR mode and recovering the BIOS was a help, but it seemed that while using BBR mode, the machine did not exhibit normal behavior. To further compliment that theory is the fact that my BIOS version hadn't changed after using BBR mode, so I'm doubtful that a BIOS flash happened when trying to use the feature.

I truly hope this post/thread can help someone else who accidentally picks a fight with HP's hideous firmware. I will update if I forgot to mention anything.
 
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Lutfij

Titan
Moderator
You're advised to disconnect the system from the wall and display, then remove the CMOS battery for at least 30 minutes before replacing it. As for the system not POST'ing I hope it's not the PSU since the motherboard in that prebuilt has proprietary connectors. The PSU in that build is nearly a decade old in spite of being labelled as 925W unit but can you verify what GPU's the system powered in it's lifetime by the previous owner?

Try and work with one stick of ram if there are more than one stick in the system. Try and connect the drive you intend to install the OS on.
 

SparkyTech934

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Jan 22, 2020
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You're advised to disconnect the system from the wall and display, then remove the CMOS battery for at least 30 minutes before replacing it. As for the system not POST'ing I hope it's not the PSU since the motherboard in that prebuilt has proprietary connectors. The PSU in that build is nearly a decade old in spite of being labelled as 925W unit but can you verify what GPU's the system powered in it's lifetime by the previous owner?

Try and work with one stick of ram if there are more than one stick in the system. Try and connect the drive you intend to install the OS on.
Thanks for your response. I'll try and break down the points you highlighted here:
  1. Yes I will be trying to clear the CMOS again, and waiting longer this time, but I'm extremely doubtful that it will be helpful. I believe that the settings that will be reset by clearing the CMOS do not include the settings that were messed up in the first place.
  2. As for the PSU, the system itself boots fine, and goes through the hardware checks, but simply fails when looking for video output devices. There is a built-in PSU test button that I will use tonight to verify that it is working properly. As far as past owners, I believe the computer was only powering the one GPU, a GTX 660, so certianly the PSU was not always maxed out on power draw. That being said, it is a dual CPU system. I doubt that the PSU went bad in this case
  3. I have previously tried starting the system with just 1 stick of RAM. I will try that again.
Lastly, I came across this article that seems to be extrordinarily close to what I'm experiencing. I do not have an old PCI video card that I know of, which is quite unfortunate, but I will see if I happen to have one laying around. If you have any more suggestions, I would highly appreciate it. Thanks again for your time, and I will update as I make progress (hopefully). Upset that HP designed the system poorly enough to brick it on one setting change alone..

Edit: I see that in the link that I posted to the article, there is an additional section at the bottom with other references, and one of the links posted is to Tom's Hardware forums, where you actually respond to the OP, Lutfij. Funny how things come full circle, eh? :tearsofjoy:
 
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SparkyTech934

Prominent
Jan 22, 2020
78
10
565
24
Alright, so I was able to remedy the issue. I tried a few things, and since there was no video output, I'm not 100% sure exactly what the fix was, but I have a hunch, and will explain in summary. My order of operations is below:
  1. Removed all unneccesary components from the machine (this would be the setup I used for the rest of the troubleshooting). This included:
    1. Optional CPU board + RAM that was installed on it
    2. Wireless card
  2. Took out CMOS battery, waited more than 30 minutes
  3. Simultaneously to clearing CMOS, removed the GTX 660 (the original card that was being rejected by the BIOS), and replaced it, in the same slot (top slot) with a low profile video card.
  4. Replaced the CMOS battery, booted the machine
At this point, the video card error 6 beeps, accompanied by red LED, 2 second pause came back. No success. I continued below
  1. Moved the jumper on the BBR (Boot Block Recovery) header, shorting the pins towards the rear of the case.
  2. On another computer, created a flash drive image with the HP software on the Z640 support site. (extracted files and then followed prompts to make 'recovery drive'). Then plugged the USB drive into the back of the machine
  3. cleared CMOS again (CMOS button on board this time)
  4. Booted the machine into BBR mode. 8 beeps, accompanied by red LED (normal activity for BBR mode). The flash drive began pulsing/flashing before staying lit constantly. Eventually (after a few minutes), the machine's fans ramped up to 100% speed.
    1. NOTE: At this point, with the observed behavior, it did not appear to be doing what it should in BBR mode. All documentation regarding this mode say that if successful, the machine would boot twice and then shut down. I am unsure if BBR + USB recovery fixed anything.
  5. I force powered-off machine since it was in error state
  6. Replaced the jumper back to original pin location.
  7. Started the machine again (now in normal boot mode). 6 beeps, accompanied by red LED, 2 second pause persisted.
With trying BBR mode without any knowledge of of success/failure, and clearing CMOS still having no effect, I was begining to feel like this was going nowhere. My last attempt is detailed below:
  1. Cleared CMOS again (CMOS button on board)
  2. Switched out video card for another low-profile option that I had laying around (this one identified as a Geforce 210 GPU by Gigabyte, revision 6.0)
  3. Booted machine.
  4. Success! I saw an HP splash screen, and was able to access the BIOS after one more CMOS reset.
After getting to this point, I did the following, and I would highly recommend others do the same:
  1. Upgraded BIOS manually to the latest version (HP Z640 - version 2.57 as of May 2021)
  2. Set BIOS to factory defaults after upgrade.
  3. Put in the rest of the hardware.
  4. Tried another GPU (RTX 2060) and changed the original setting that messed me up
    1. 'disable legacy support, enable secure boot'
  5. Everything still worked fine after that.
Summary
Alright, so to summarize and play some detective work, I believe that the fix was as simple as replacing the video card with another unit that the system was able to interface with in UEFI only mode. I would like to think that using BBR mode and recovering the BIOS was a help, but it seemed that while using BBR mode, the machine did not exhibit normal behavior. To further compliment that theory is the fact that my BIOS version hadn't changed after using BBR mode, so I'm doubtful that a BIOS flash happened when trying to use the feature.

I truly hope this post/thread can help someone else who accidentally picks a fight with HP's hideous firmware. I will update if I forgot to mention anything.
 
Last edited:

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