Hi iFixit community
I am in need of your help since I am looking to downgrade the Firmware of my MacBook Pro. Unfortunately the hold the power button down does not work, can you let me know how can this be done?
The version I'm installing is 2.7, from the looks of it, my PC has a newer one than the one mentioned.
Note: I have the needed version from apple.
Best regards
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1. You need to download EFI for your mac http://support.apple.com/kb/ht1237 (unless they haven't updated the page).
2. Be sure you downloaded right EFI, otherwise it could end up bad!
3. Get unpkg http://www.timdoug.com/unpkg/
4. Use unpkg on *.pkg with your EFI, then copy the folder you got to /Applications/Utilities/
5. Open copied folder, find a .scap file.
6. Open terminal, copy there sudo bless -mount / -firmware then press spacebar.
7. Drag .scap file to terminal.
8. Press spacebar and copy --recovery --verbose in terminal.
9. Press enter, type password and press enter again.
10. Shut down your mac from menu, wait until it will turn off.
11. Wait a bit, then turn on your computer but do NOT hold the power button down. The screen will turn black and remain in that state for up to 40 seconds. A gray screen will appear and a status bar indicates the progress of the update.
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Hi @mayer
Thank you for the reply. I'm right now doing as you listed above. I found my self that after using the app it shows a "RecoveryUpdatePayload" file but not as you mentioned above, this is also a 102 MB file (Should it be this size?). I tried searching for another possible version and found this page https://support.apple.com/kb/dl1499?loca..., although compared in size between this one and the one you snet me it is rather much smaller. I followed the steps to Unpack the file and it does show a ".scap" file. Do you think I can use this file? Are updates for the EFI, like BIOS updates? that basically errases and writes it all back?
Regards
I am also thinking the possibility of wipping the disk completly and I mean completely, perhaps erasing all partitions and use it as "Brand New" will re-install the Firmware?
Regards
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