BIOS changed to enable Secure Boot, causes 6 beep codes

[WpgTriniman1]

HP Z400, product # B9W43US#ABA

In order to load a new image from a bootable flash drive that my organization uses, I had to enable Secure Boot in the BIOS.  I have used the bootable flash drive on other computers without any trouble.

Now, the computer beeps 6 times and goes no further.  It doesn't get to the point where I can boot from the flash drive.  It doesn't show anything on the display.  It will beep 6 times, with the On button flashing red, about 5 times, and then silence.

[Paul_Tikkanen]

Hi:

Usually that happens if you installed a graphics card that did not originally come with your PC.

You will need to remove the graphics card, and disable secure boot again.

You cannot enable secure boot with whatever graphics card you have installed.

If the PC has onboard graphics, you can leave secure boot enabled with the video card removed.

[WpgTriniman1]

So the computer had Windows 10 on it with the video card working just fine.  I'm trying to install a new Windows 10 image from a flash drive. 

I made the mistake of thinking enabling Secure Boot was enabling the TPM chip.

On another, identical computer, I enables the TPM chip and it's imaging right now.

My question now is, how do I get back into the BIOS?  When the computer starts, after 16 seconds, it begins to beep.  It will beep 6 times, pause for a second or two, then repeat.  There are 5 iterations of it beeping.  While it is beeping, the power button flashes red.  It continues to flash red after the beeping stops.   Pressing Esc, F9 or F10 does nothing.  There is no image on the screen.  If I can get back into the BIOS, I can turn off secure boot and properly enable the TPM chip.

[WpgTriniman1 · Accepted solution]

Good news.

I cleared Clear CMOS button and the computer is now successfully imaging.

All good.  Thanks for your help.

[Paul_Tikkanen]

You're very welcome.