A1425 retina late 2012

[Mrmani]

Hi all
I had this Mbp a1425 come in dead where I replaced the smc and the machine was restored back to life with the os 10.15 Catalina. The customer used the machine for 1 week and sent me back with no display it giving Ram beeps 3 beeps.so I reflowed all the 16 rams chips still no luck finally I replaced all 16 ram chips and still no display same beeps. The next day I programmed the efi and bingo I got display but a new problem not booting from ssd it boots from usb but not ssd, so I cleaned the ME
Engine still same Problem .it only installs 10.12 the moment I go to put 10.13 or 10.14 or 10.15 it starts
Installation and after second boot guess what again Ram beeps WTFFFFF Apple . Anyone know what efi should I use the identify is 10,1.what is this firmware issue that gives me ram beeps also I see an invalid entry in the VSS store when I strip the bios in uefi tools

 

[Mrmani]

@tsialex pls can you help me what is the issue with these firmware’s and why do I get memory beep when i install anything more than 10.12 where as before the catalina did work.above post mentioned history
Thanks

 

[tsialex]

.

 

[Mrmani]

Thankyou for your reply much appreciated. I have removed the bios chip and tried several me
Engine specially extracted from the macOS installer scap file. But strange thing is there were so many invalid entry in the VSS store if I post the bin file here would you be able to check if it in UEFI tool
Thanks

 

[Mrmani]

Both machines are identical except the boot rom is different the black one runs catalina and the white screen does not go beyond 10.12

 

[tsialex]

.

 

[tsialex]

Just noticed the FFFFFFFFFFF SSN. This is highly suspect of someone messing the NVRAM volume trying to remove iCloud Lock/MDM or something a long the lines.

I can't help you anymore, since I don't help in any way people doing this type of thing.

 

[Mrmani]

hello
sorry but the above FFFFFFFF ssn is not my bios i downloaded it from a website. my orignal bios is the one with the s/n i marked off.I have downloaded several bios to see if my machine is a firmware or hardware issue.I can assure you that I have not changed any kind icloud lock or tampered.I request you to pls if you can repair my orignal bios that came with the laptop.