TPM completely lost on a Dell Optiplex 5050 SFF

BIOS/UEFI Modding BIOS Modding Requests
1

Hello,
i have a weird problem.

i have a Optiplex 5050 which worked just fine with a BIOS Version 1.20 and in there shown a TPM 1.2.

this machine i sold and it came back as “faulty” with the CPU-Fan spinning at full speed as soon it was shut down.
A further check shows, that the customer obviously has done something to get this machine running Windows 11.
It had a BIOS Version 1.32 and stated a TPM Version 2.0 now.
I guess he applied a Firmware-Update for the TPM not suitable for this machine.

As i guessed that the MOD had failed. I just reflashed in a chip off mode the BIOS backup i had from this machine saved before with the above shown parameters. 1.20/1.2 assuming it would work normal again.

The Fan-Problem was now gone as expected…
…
but now the TMP problem started.
On every boot the TPM was stated as not recognized. ?
And checking the BIOS-Setup, the TPM menu was completly gone.

I tried now everything, know so far to me.
Cleaning the ME, updating to BIOS 1.32 again, thinking, it could be a mismatch between the old 1.20 BIOS and the new firmware of the TPM.

Nothing worked in the way that anything of the TPM reappeared again. Instead the “not recognized” error was still there.

the only way to get this machine booting “normal” without this error again was downgrading the BIOS to a VERY old Version.

But this Version does not show any TPM either, what is really not the goal of all.

I would appreciate every idea, clarifing to me, what has happened here and how to get back the TMP.

If a BIOS file of all my backups or the actual state is neccesary i will prepare and upload this.

2

Hi,
Can you tel me wich kind of TPM your 5050 uses (is it Infineon SLB 9665, NUVOTON NPCT650 or a other TPM) ?
Have you tried using the Dell TPM firmware to match BIOS 1.32 again ?

Is the TPM still functional at firmware level ?

3

Hi,
on the board it is the NUOVOTON NPCT650.

All the TPM 2.0, even the 1.2 TPM-Firmware updates provided by Dell i had already tried. Everyone matching to the BIOS-Version level.

Eg.
BIOS 1.20 had the TPM 1.2 >> i tried all the update for 1.2
BIOS 1.32 had the TPM 2.0 shown in the BIOS, when i got the machine back >> i tried the 2.0 updates

Same result. “TPM not found”…

Also “Hardwareinfo” is not detecting anything related to the TPM.

The Chip is definitivly there. right next to the BIOS
In its surroundings i not can track any hardware manipulations.

So i guess the hardware is ok.
But as asked … the “firmware-level” is not working anymore.

any idea how to fix this?
is this a part of the BIOS, or has the module-chip itself to be reprogrammed?
if, how can i do this.