Good old HP Compaq dc7900 - Unable to enter setup BIOS

[Nico059]

Dear HP Community ! you're my last hope ....

I refurbished an old HP Compaq dc7900 (Minitower version) cor2duo 2.3 Ghz - 4GoRAM+ 240G SSD.

It works fluently with Win10 What an amazing piece of harware 😉

BUT ... there is a BUT ....

I'm totally UNABLE to enter the SETUP BIOS.

Whatever I tried, press F10 at boot time , clear CMOS (button or remove battery CR2032),

Context:

I have updated the BIOS to the latest BIOS REV V01.27

I have USB Keyboard.

In the past I managed to enter the BIOS Setup, it was hard but randomly after several reboot/attemps I was able to enter it

I'm also able to enter F9=Boot menu to choose order of boot (USB/Hard drive etc), or F12=Network.

BUT if I press F10, I see briefly "Setup" on the bottom/right of the screen.... but I don't enter in the BIOS SETUP at all... Windows start then immediatly

What can explain that, what can I do ...

(I want to change VT-x config in bios and some small parameters)

[Paul_Tikkanen]

Hi:

The only suggestion I can offer, would be to try a PS/2 Keyboard and see if you can get into the BIOS with that.

I have a dc7900 and use a PS/2 KB and mouse and have no problems accessing the BIOS via F10.

[Nico059]

Thanks Paul for your quick answer

May I ask you the version of bios ?

Unfortunatly .. I don't have an PS/2 KB ... And as there is an effect when I press F9, F12 with my usb KB it means it seems to be  "recongnized" during te boot sequence. Even when I press F10, I see a "Setup" display very breifly in the bottom/right corner of the screen ... but after that ... no bios setup screen ... just the normal boot of Windows ....

"

[Paul_Tikkanen]

You're very welcome.

Mine has BIOS v1.27 installed...the latest one.

See if you can borrow a PS/2 KB from someone because it may work.

On some of these older HP PC's you can't get into the BIOS without a PS/2 KB.

That is why I have never switched mine out.

All of my PC's have PS/2 ports, so I use PS/2 keyboards and mice on all of them to free up USB ports and not to encounter any problems if I need to get into the BIOS.

[SDH]

I second Paul's recommendation.  I've found a few of the more recent HP Z workstations (such as ZX00 and ZX20 versions) that have been hard to get into BIOS on can be accessed via use of PS2 keyboards/mice.  PS2 is a more primitive and alternate pathway than USB.  If I'm going to be getting into BIOS a fair amount for a while I might also add a 5-second POST delay, and I always turn on the BIOS option to allow use of the ESC key to access BIOS (eg, in the ZX20 family).

I happened to watch a HP YouTube video some years ago and the HP presenter, workstation expert, happened to explain why the HP workstations still had PS2 keyboard and mice ports.  He used the term "3-letter agencies" that require that because they filled all the USB ports with epoxy to prevent thumb drive security breaches.

So, there also are excellent new HP PS2 keyboards and mice you can find at a low cost on eBay... whenever I'm building up a new clean install I only use PS2 keyboard/mouse to keep pesky USB issues out of my hair.

[Nico059]

Sure I will definitly try to find an USB KB (I have somewhere a "Dongle" USB to PS/2 port ... I will try if I can find it ...)

I will let you know results...

Nicolas.

PS: .... Oh my god, epoxy in USB port .... !

[Paul_Tikkanen]

Hi:

You can try it, but I have found that a USB to P/S2 dongle won't work.

At least it didn't for me.

You need a PS/2 KB to go directly into the PS/2 port in the back of the PC.

[Prométhée]

Hi

https://lecrabeinfo.net/acceder-au-bios-ou-a-luefi-dun-ordinateur.html

N°2 : via Windows 11 ou 10

Maybe you can try this if you have windows 10

[DGroves]

in my years i've come across this several times and changing the usb keyboard to another brand or using a ps2 one was the solution

many cheap usb keyboards play fast and loose with the usb spec, and this can cause issues with some systems that adhere to the usb spec closely and are unforgiving of usb devices that are not within specs

[NonSequitur777]

@Nico059,

Like @Paul_Tikkanen, I also happen to have an upgraded HP Compaq dc7900 (USDT) -Incidentally, my first Legacy HP Desktop Upgrade Project, and also never had any issues accessing BIOS. (Reference: https://h30434.www3.hp.com/t5/Desktop-Hardware-and-Upgrade-Questions/HP-Compaq-dc7900-Ultra-slim-Des...).

If you have tried a WIRED connected keyboard and mouse, and still can't access BIOS, it may suggest a faulty motherboard, imo.

[EDIT:] Try out your wired keyboard on each USB port too, btw.

Kind Regards,

NonSequitur777