Optiplex 3050 Mini Tower - TPM disappeared from BIOS

In most cases a simple static charge removal would do . 

Disconnect  everything from tower including power cable. Hold power button for 30 seconds. 

Connect everything back and power it on. If not fixed 

Try Dell TPM 2.0 Firmware Update Utility

https://dl.dell.com/FOLDER04166647M/1/DellTpm2.0_Fw1.3.2.8_V1_64.exe

INTEL PTT replaces TPM  you can have both on a machine but you cannot have both active at the same time.  Enable PTT.

• Intel® Platform Trust Technology (Intel® PTT) - Intel® Platform Trust Technology (Intel® PTT) offers the capabilities of discrete TPM 2.0. Intel PTT is a platform functionality for credential storage and key management used by Windows 8* and Windows® 10. Intel PTT supports BitLocker for hard drive encryption and supports all Microsoft requirements for firmware Trusted Platform Module (fTPM) 2.0.

TPM is not available in all countries or on all models even if they are on your specific model.

How to Configure the Trusted Platform Module (TPM) Security When It's Greyed Out or PTT (security) is Greyed out.

This is expected behavior, Intel Platform Trust Technology (PTT) is enabled by default on many dell models which causes the "TPM Security" and PTT Security option to be disabled, since both TPM and PTT cannot be enabled at the same time.

Tap the F2 key when the Dell logo appears to enter the BIOS
Expand the "Security" section, click "PTT Security", and deselect Intel Platform Trust Technology
NOTE: If PTT is still greyed out as well, re-enable PTT by disabling Intel Trusted Execution under Virtualization Support.
Click Apply and Exit to reboot
On reboot, tap the F2 key when the Dell logo appears to re-enter the BIOS
Expand the "Security" section, click "PTT Security", and select PTT Security
Click Apply and Exit to reboot into the Operating System.

Hi @XPS_Man  and many thanks for your suggestions. I tried the static discharge, but it hasn't solved it. I repeated it with the CMOS battery removed, and also put in a new CMOS battery just in case, but that did not work either.

I then tried the TPM 2.0 firmware. In order to run windows, I have to "Continue" after the BIOS TPM error message, and log on to windows using the password for the system. No other security method is working whereas previously the PIN code was the standard method I used for logging on.

I run the .exe file from windows explorer, and shut down the explorer window so that the only programme I'm executing is the TPM update. It produces this error:

First error

I click OK and get a second dialogue:

Second error

At this point I moved on to @speedstep suggestions below, but really appreciate the suggestions.

HI @speedstep and again, really appreciate the input. Neither TPM nor PTT exist in the security branch of the BIOS. It's not a case of being greyed out, they simply aren't there. Apologies for the orientation!

BIOS Security branch

I did try disabling the intel Trusted Execution check box, but that prevented Windows from booting and it would not go past the Windows logo at boot.

After reenabling the check box, the machine booted back into Windows using the log on password. In the Windows Device Manager, there isn't even a "Security Devices" branch. "Security Devices" branch is missing in Win10 device manager

Thanks again for all your input. I'm not sure if it is the onboard TPM that has failed, but I'll investigate to see if installing the PTT is feasible.

Cheers

Ray

Yes Most likely a new motherboard is needed. 

Yes that seems to be the correct way there is no point replacing the motherboard to get a feature which you don't use. 

One of my cases with dell premium support an XPS 9570 had to go through 2 motherboard replacements, a 3 month log level 3 case for the same issue. 

@Anonymous  TPM/PTT implementation on future boards should be improved. With windows 11 making it a mandatory requirement, an Out of warranty customer may end up being without a computer. 

so please fix it on hardware level 

@XPS_Manlooks that way. There are huge numbers of threads on this topic, seems it is a regular problem although it is my first time with it. I've got the windows security pin working again, by deleting and resetting within windows, so the "only" problem is that on boot, it requires the user to press "continue" from the BIOS error. I could turn off the BIOS warnings, but I'm reluctant to do that. I've decided to just live with it for the moment, as in all other respects, the PC seems to be working perfectly and I can live without Windows 11

Thanks again for your help.

Ray

@XPS_Man @speedstep Thanks again for your input. I'm based in the UK and sure enough, out of warranty by 6 months. The PC had TPM 2.0 working on it, and has not had any new hardware or software added except for routine Win10 Pro 20H2 updates. (Just to clarify, the BIOS updates were carried out *after* the TPM failure to attempt to rectify that.) The whole TPM situation seems a sorry mess at the moment! Would be nice to have a BIOS level control to turn off that error message, but hey, one extra boot time key press or replace the motherboard. No brainer! Keep safe. Ray