BIOS Issue 820-3437


If I upload my original BIOS for an 820-3437, can someone fix the Fsys, clean the ME and add a serial number to it? I've been trying to do it with my Medusa 2 but cannot get it to work.


2informaticos, it looks like your file worked. It shows the correct serial number in About this mac, as well as system information. Would you be able to tell me what you did you fix the file? what it just the fsysblock and check sum? Thank you by the way. The computer has Yosemite on it so I am going to update to Mojave or newer to see if it still works.


Staff member
I changed serial number into a clean ME working BIOS.
Finished fixing checksum of Fsys area.

I also built a version starting from your backup, thinking about possible APFS issue.
Is not the case now, if machine has Yosemite installed.
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