Z400 compute option in BIOS bricks (again) the system

[2-Xite]

Dear all,

Yes, it's the same terrible mistake that brings me here... and after trying of many, many hours I've decided to write a post.

So, I can not boot anymore after the enabling settings 'compute - true' in the BIOS 3.61.

No clearing CMOS, reflashing (also downgrade to few older versions of BIOS with or without the P.W. jumper on), taking battery out for few days, putting an older VGA controller in another PCI-slot, changing the position of the original ATI FirePro V4800 1G, nor trying to make a 'blind' reset of the  'compute' in the BIOS and so on... I was reading all the posts here about similar problem on this model too!

Until now, I can only see a blue screen during of the flashing (both USB and CD-flash possibilities works), but after reboot the computer makes 6 cycles of 6 beeps and does not show the BIOS anymore.

Could someone help to reset this mousetrap and let me reanimate my precious computer? I have to run a music-notation program on it for my leaving.

Thank you very much for assistance!

2-Xite

[DGroves]

and we have ANOTHER winner of the ready fire aim group

playing with Bios settings you don't understand is a great way to kill/ruin a working system

what the "compute" option does is DISABLE the video output of any video card in the slot so the system sees the card only as a gpu coprocessor

by enabling this on every slot you have effectively removed all video capabilities from all pci-e slots

and as you have discovered a cmos/bios reset will not revert these changes

your only hope is to remove the pci-e video card and install a PCI (not pci-e) video card in one of the z400's two pci slots and then boot, enter the bios and change the pci-e compute settings back to disabled

or hope someone can write down the exact keypress needed to blindly change the primary video slot back to the default compute disabled setting

if all else fails, replace the motherboard

[2-Xite]

Dear Mr Groves,

Thank you for the shared information.

It's not that I’m trying to justify my silly step to change some values in the BIOS, but after a recent update of the OS the graphics performance was not as expected: Windows 10 just replaced the original V4800 driver with “own” ones, so I could not work on my machine anymore… even after manually putting the original driver back. With my experience on a great Z420 system, that clearing the CMOS does reset the BIOS completely.

Anyway, I have some questions, maybe you know the answer.

What happens after those 6 cycles of 6 beeps? Can I still approach the BIOS “in blind” after of the system stops with beeps (but actually it continues blinking red lights out of On/Off button in same tempo as the beeps...)? Or does the stop of beeps means that the system not approachable anymore until the hard reset?

There is a post on this forum that describes those steps of resetting the BIOS in “blind”-mode, so I can will try to utilize it.

As mentioned earlier, I’ve tried an old PCI (Club 3D GeForce 6200 CGN-628P) to approach the BIOS through another PCI-slot w/o success yet, so maybe I have to find even older vga-controller to change the settings? What do you think?

Thank you in advance!

2-Xite

[DGroves]

six beeps = video display error

the six beeps happen because you set all expansion slots to "compute" so there is now no available video display device for the bios to find on matter which slot you place the video card in when the system starts up

did you set all slots including the pci ones to compute? if so then the pci card trick will not work, only the blind keyboard method will now work

and i stand by my statement that changing the bios options to compute because windows updated your video driver is a classic "ready fire aim"

i also have bricked systems and corrupted installed OS's while playing with them but i never used my main system for experimenting so when it happens it's only a minor annoyance and i try to find documentation BEFORE doing something and if i can't find it i will never try it on a main system. i'm sorry you had to learn this the hard way

last, the latest video card driver for the v4800 (FirePro professional card) for windows 10 can be found at the AMD website under the "Legacy" section, note that this card is not supported any more, you should update to a newer card the latest win 10 x64 driver revision is 15.201.2401.1010 from 2017

https://www.amd.com/en/support/professional-graphics/legacy-products/firepro-v-series/firepro-v4800

[2-Xite]

Thank you Sir for such extended replay with the link. I was thinking that my video-card does support the compute-option... In any case, I have to learn this lesson now....
If I could succeed in repairing the computer, I will let you know.

Many thanks again,

2-Xite

[DGroves]

follow the posted z400 blind keypresses sequence

however keep in mind that the directions may not take account that you will have a video error (6 beeps) msg that is not visible telling you to press the F1 key (as i recall) to continue so you will need to press the F1 key before doing the blind keypresses

BTW HP does post what all the bios options are (imagine that) you might want to download them i recommend at a minimum you get the service manual

https://support.hp.com/us-en/document/c01747663

[2-Xite]

Oh, thank you, Mr. Groves!

It's a valued addition!

I was hitting (and/or holding) F10 and not understood why I could not further... It's the F1 key to enter the BIOS from "beep-mode" and not F10!

I will continue tomorrow with it, first I have to "study" the BIOS-layout from your link.

Keeping fingers crossed...

[DGroves]

you still don't get it...........................

the video error will trigger BEFORE ANYTHING ELSE, and you must first acknowledge this error with the f1 key, before you proceed to the enter bios f10

you will not have much time to press f1 before the f10 option times out 

personally i would just replace the board with a used v2 motherboard (has 6 not 4 dimm slots)

ver 2 board (6 dimm)

https://www.ebay.com/itm/HP-Z400-Desktop-Motherboard-586968-001-586766-002/353076811501?epid=1034376...

ver1 board (4 dimm) don't buy!!

https://www.ebay.com/itm/Genuine-HP-Z400-Workstation-Intel-Motherboard-461438-001-460839-002/2739534...

[Pcdiy1366]

Try to reseat cpu and ram

[DGroves]

reseating the cpu (and ram) will not fix this person's problem and your suggestions can actually cause more problems as the cpu socket is only rated for a specific number of insertions/removals and you also run the risk of damaging the cpu socket pins when doing a cpu removal, so this should only be done when there is a valid reason to do so

the compute option Turns OFF the video cards display for the slot you enable compute on making the card a GPU coprocessor and no longer a display card, the "OP" set all slots to compute so the system now errors out on boot due to the computer being unable to find a working display adapter

compute should only be enabled, if using specific software that supports a SECOND or THIRD video card... it's never enabled on the slot with the primary video card