System won't boot to bios

[A_S_A]

After following the instructions from MS to clear the TPM in Windows 10, the system tried to reboot and will not get to the BIOS screen.  The power light is on constantly and there are no beeps during an attempted boot.  The fans spin up briefly and then go to a low idle.  Monitor only shows a black screen and unresponsive to keyboard or mouse input.

I've spent a few hours scouring the internet for anything that looks helpful without success.  HP support informs me that my warranty has run out and I need to take it to a tech.

Any help would be much appreciated.

[DGroves]

since you don't provide the directions you followed, don't expect any useful help as the last time i checked nobody on this forum has mind reading abilities

all i can recommend is a FULL CMOS RESET

power off, remove power cord, press pwr button for 10 sec then remove cmos battery from motherboard and then press cmos reset button (if you have one) reinstall cmos battery, reconnect power and try power on and if boor screen shows press bios key to enter bios and set time and any other nessary settings, save and reboot again

[A_S_A]

Thanks for the suggestion.  I tried a full CMOS reset before posting my question without a change in outcome.

The instructions I followed, per Microsoft, were to go to windows settings and click through the following options:

Settings->Update & Security->Windows Security->Device Security->Security Processor Details->Security Processor Troubleshooting->Clear TPM->Clear and Restart.

[VH2000]

What was the reason to run >>Clear TPM<< ?

Did you run the update to TPM 2 by SP87753 first?

[A_S_A]

Clearing the TPM was one of the instructions for prepping the machine to be sold.

No, I didn't update to TPM 2 prior to clearing.

[DGroves]

remove all bootable devices (HD's and USB devices)) does it go to a no bootable device found prompt?

if you were using drive encryption, resetting TPM will prevent the system from booting

[A_S_A]

Removing the drives and USB gives the same result.  Power light comes on and stays on, fans start to spin up and then slow down.  No beeps.  Black screen only.

[VH2000]

unplug powercable

wait for 5 seconds

press power on

remove boot drives

press the CMOS CLEAR Button ( 1" below COMOS battery) for 5 seconds

plug in power cable

press power on

wait and see

[A_S_A]

Followed the steps explicitly (CMOS resest) with no change in results.   As well, with other iterations of attempts, I have replaced the CMOS battery and removed the password jumper to try to isolate variables.  No change in outcome so far...

I've read other threads with similar, but not identical, symptoms that were solved following the instructions from the advisory here https://support.hp.com/us-en/document/c05163478.  I've ordered a 128MB, FAT32 USB drive to load the bios .bin file and a PS/2 keyboard thinking that I might need to attempt to reflash the BIOS using the BBR Jumper for a crisis recovery.

Before I go that route, is there anything that others think would be worth trying first?

[DGroves]

no, you do might have a corrupted bios for some reason however this is just a educated guess based on limited information

if you have a local HP shop or a good non hp shop you might want to have them look at it

doing a bios recovery, can cause MAJOR PROBLEMS if you have another issue like a failing (failed) cpu, bad ram defective pci-e card and so on..............