DME - CAS ISN issue

[HPTuningCR]

Hi!!!

I´m helping a friend resurrect an E90 with an MSV80 DME (328i).  The car had the CAS completely bricked, no way to read flash or eeprom.

We found an identical CAS to program to the car.   I was able to extract the ISN from the DME but the ISN I have is 16 byte and the CAS requires a 2 byte.  Having no way to "convert" that ISN the car won´t start.  Found another CAS (from an E70 IIRC) so I tried using that and was able to get the car running but now 2FA4 code is present on the DME and car lacks power.  No codes on the EGS. 

From what I´ve searched this happens when the CAS and the DME are not compatible or have different software versions so I´m now stuck.

Can anyone "convert" the ISN from 16 byte to 2 byte so I can use the same version CAS?  Or anyone has any idea on how to match a different (and apparently newer) CAS to the car?

This is the ISN information I have that has successfully started the car but with 2FA4 code and lack of power

*******Edit: Unnecessary Info*******

Thanks!