[Q] Need help with imei

Hey there,my motherboard from my s3 i9300 was broken and a buy another one from a guy who broke the display on this mobile.The only problem it s that the motherboard it s from GT-I9305 LTE and now i replace it but i get that imei null/ and no baseband.I try already with stock rom,efs backup.I meantion that when i first power on the phone it was working fine it has signal,detect carrier,imei etc.But after i remove to battery to put all the screw it does't work any more.
Any other ideas?