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820-00687-A BIOS
820-00687-B
Schematics boardview
820-00687-B
Schematics boardview
820-00687-A
- Thread starter ThienBui
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- 820-00687-a 820-00687-b bios rom
yes, can
Use Medusa to clean ME, after that it will work.
Everyone who is using EFI BIOS SPI flex cable (without removing the chip from the board), make sure that the cable is making a good connectivity between pins and the programmer.
It happened in my case to not be able to read or write.
Just find the right orientation/position.
And also, after the whole process, make sure that you reset the nvram for 2-3 times, because some times pieces of information gets stuck and it acts weird (boot loops, black screen, stuck on logo, starts very slow) and this might fix.
In rest, good luck guys!
It happened in my case to not be able to read or write.
Just find the right orientation/position.
And also, after the whole process, make sure that you reset the nvram for 2-3 times, because some times pieces of information gets stuck and it acts weird (boot loops, black screen, stuck on logo, starts very slow) and this might fix.
In rest, good luck guys!
Last edited:
Unavailable
RAM management chipset
model no have boardview and Schematics
u have schematic & brd , A 1534 . (820-00687-A). pls
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MAK_US1977
Registered member
Hi
I have 820-00687-B
this board have broken efi chip, i replace it with good one
machine power up with ? mark
I flashed efi chip with APPLE 820-00687-A,bin , machine power up , i see apple logo with no backlight
i tried no_serial bin also same issue
any solution for this machine or it must flashed with revision B bios dump?
I have 820-00687-B
this board have broken efi chip, i replace it with good one
machine power up with ? mark
I flashed efi chip with APPLE 820-00687-A,bin , machine power up , i see apple logo with no backlight
i tried no_serial bin also same issue
any solution for this machine or it must flashed with revision B bios dump?
