Need Downgrade Firmware and drivers to original LION

[Andrea_73]

Hi Everybody. I'm new here.
my problem is...
I upgraded my MBP 15" late 2011 with a SSD and installed HighSierra. Everything workin fine.
Then I created the Problem..
I Forced the installation of Catalina using a Patched-Catalina.
After this stupid operation the Thunderbolt Stopped Working.
I wish to bring back my MBP to th original running OSX LION and then reinstalling HighSierra.
With recovery mode I can install LION, but... I'm not able to install the LION's Firmware and drivers, 'cause are
older then the one installed by the Patched Catalina.
I wanto go back to the original configuration and then install HighSierra, so I could, with a fresh installation to install as well the HighSierra drivers and firmware.
I need to force installation of LION's drivers and firmware, but I don't know how to do that.
Could anybody help me?
Thanx.

 

[Bigwaff]

Where did you get the "Patched Catalina" from? I was not aware one could force the install of firmware not meant for unsupported hardware onto unsupported hardware. Open System Information.app and select "Hardware" at the top. Locate the "System Firmware Version" or just post screenshot of page. Would like to see your Firmware and Boot version info.

 

[Andrea_73]

Where did you get the "Patched Catalina" from? I was not aware one could force the install of firmware not meant for unsupported hardware onto unsupported hardware. Open System Information.app and select "Hardware" at the top. Locate the "System Firmware Version" or just post screenshot of page. Would like to see your Firmware and Boot version info.

Now Now HighSierra is installed, but Thunderbolt still doesn't work.

 

[Bigwaff]

Boot ROM 87.0.0.0.0 is latest supported version for your MBP. Installed with High Sierra. You can’t “downgrade” firmware. Your issue is not firmware version. Try reset NVRAM,

Reset NVRAM on your Mac - Apple Support

If one or more settings stored in NVRAM don't work as expected on an Intel-based Mac, resetting NVRAM might help.

support.apple.com

,boot Internet Recovery (Option-Command-R; best to use hard wire Ethernet, not WiFi)

Use macOS Recovery on an Intel-based Mac

Learn how to use macOS Recovery on an Intel-based Mac.

support.apple.com

, erase internal disk using Disk Utility (make sure to View > Show All Devices and select top most in tree), try install MacOS again (should be High Sierra).

 

[Andrea_73]

Thanx. I'll Try!
But may be the boot ROM 87.0.0.0.0 is the corrupted one installed by the Patched-Catalina, masquered with the name 87.0.0.0.0 to be accepted by the system. Do you think coud it be possible?
That's why I would force the downgrgrade of firmware, install Lion and then initialize again the ssd and make a fresh installation of High Sierra. But. Ill' try to do what you told me

 

[Grumpus]

In addition to resetting the NVRAM as @Bigwaff advises, you should also try resetting the SMC.

You've not told us what "catalina patcher" you used, but I would guess that it's this one. On machines (like yours) which don't natively support the APFS filesystem, the dosdude1 patcher puts an APFS driver into the EFI partition. It's important to ensure that the EFI partition is erased if you want to go back to High Sierra. During the installation, you'll be running Disk Utility to erase the drive. In the Disk Utility View menu, select Show All Devices. Then click on the actual top-level drive name to select it, then click the Erase button. After the drive is erased, you can exit Disk Utility and proceed with the installation.