tried it and it works perfectly, thank you very much...

ok thanks, I'll try it and update you

sorry I must have got the two bios mixed up, now I'll send the correct bekup...

the serial number is R90T71ZK
thank you

Hi everyone, this laptop turns on but the screen is black, having an identical board I tried to replace the bios chip recovered from this second board and the notebook turns on but the video arrives after some time, I thought it could depend on the fact that I did not copy the DMI from the other bios so I read the guide several times but I can do some steps then I get lost I have to start again from the beginning, but unfortunately I can not go further than a certain point, I attach the bios bekup that does not work which has the correct serial numbers...