USB not working after SMBIOS change to iMac20,1 (EliteDesk 800 G4 i7-8700, OpenCore)

[Bruno Arias Jimenez]

Hello everyone,

I’m running macOS Sequoia 15.5 on my HP EliteDesk 800 G4 SFF using OpenCore.

Specs:

• CPU: Intel Core i7-8700 (Coffee Lake, 6 cores / 12 threads)

• iGPU: Intel UHD 630 (no dedicated GPU)

• RAM: 32 GB DDR4

• Storage: 2 × NVMe SSDs (1 × Windows 11, 1 × macOS)

• SMBIOS currently: iMac19,1 (working fine)

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Problem

I want to prepare for macOS Tahoe, so I tried changing SMBIOS to iMac20,1.
After reboot, all USB stopped working (no keyboard or mouse detected).

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What I tried

1. Disabled USBMap.kext and enabled XhciPortLimit + USBInjectAll → didn’t work.

2. Created a UIAC.aml → didn’t work.

3. Remapped my USB ports from Windows, generated a custom kext, disabled XhciPortLimit and USBInjectAll→ still nothing.

4. Tested SMBIOS iMac20,2 → same issue.

5. Considered MacPro7,1 SMBIOS, but didn’t try because of possible iGPU/UHD630 issues.

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Current status

I reverted to my original EFI with iMac19,2, and everything works normally again.

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Questions

- Why does USB completely break with iMac20,x SMBIOS on Coffee Lake?
- Is it possible to make iMac20,1 SMBIOS work properly on this hardware, or should I stay on iMac19,1/19,2 and wait for OCLP/Tahoe patches?

Thanks in advance for any help!

[MaLd0n]

Change smbios on USB kext too

[Bruno Arias Jimenez]

Thanks, that was it