S3 cant flash Custom Rom, always unknown

[johnkill_dxb]

i am really frustrated with my s3, since July i am trying to install custom rom(tried 5-6 ROM), but after i finished and reboot, always i've got UNKNOWN baseband and IMEI! i need to reflash again to stock firmware and the baseband and imei will be fixed.

this is my S3

 

[boomboomer]

No information or history provided, unable to offer help.

What has happened to the phone before, what version stock makes it work and which custom roms have you tried.

 

[johnkill_dxb]

sir may phone has stock firmware, orig from box, i just wanna install some custom rom like cyanogen etc... but everytime i installed rom, i always got problem, baseband and imei becomes UNKNOWN! i need to flash again with stock rom from sammobile, to fix everything, after flashing stock, it is working properly, but stock orig firmware.

 

[tallman43]

sir may phone has stock firmware, orig from box, i just wanna install some custom rom like cyanogen etc... but everytime i installed rom, i always got problem, baseband and imei becomes UNKNOWN! i need to flash again with stock rom from sammobile, to fix everything, after flashing stock, it is working properly, but stock orig firmware.

Like boomboomer said more detail is needed their are many reasons why you lose imei one of the main ones is upgrade from efs v1 to efs v2 if you post the information that @boomboomer as asked for then he and others including myself will be able to answer your question better.

 

[johnkill_dxb]

i just followed the procedure here:

http://www.android.gs/install-paranoid-android-4-6-beta-rom-for-samsung-galaxy-s3-i9300/

also this one procedure

http://beta.download.cyanogenmod.org/install

 

[johnkill_dxb]

better i stay on stock firmware

 

[id0]

Have you tried to back up your ESF folder or use ARIZA Patch?

 

[Darke5tShad0w]

better i stay on stock firmware

Are you doing a clean install with each rom and factory reset?
We still need details.

 

[johnkill_dxb]

yes clean restore with factory reset