820-3330 manual serial replacement Bios edit

[jadao]

This 2012 15'' 820-3330 was brain dead with all rails, not booting, no usb mouse activity.

I read the bios with the medusa and had an "Error read blockxxxx not found..." (apologies didn't write exactly the error)... Tried a random testing 820-3330 bios and it worked and booted correctly.

I want now to put back the customer serial but it seems the bios dumps on these machine looks like they are from another type, I mean that I don't find any $SVS or even the Serial C02 in hexedit...Should I look for another set of strings?

My plan is to replace manually the serial or even better the entire Fsys block and after that I will use Medusa to Clean ME and fix any CRC mismatch.

How would you do to replace the serial?

Thanks in advance

 

[2informaticos]

Did you search for "SSN" string in the BIOS file?
"Fsys" and "$SVS" must also appear.

Compare with another BIOS downloaded from Internet.
Locate Fsys area and replace with the one from backup; supposing is not corrupted.
Don't need to fix the Fsys checksum in this case.