S4 mini can't detect sim card

[hardys77]

Hello. I changed a sim card from S3 mini to a S4 mini and the problem was that S4 mini couldn't find the network for the sim card so I put back the first sim which was in the S4 mini and was working and now it won't detect it, it says "No sim card" then I switched the sim from s4 mini that couldn't detect it to s3 mini and it's working. I have no idea what to do now. Many thanks if you can help me.

 

[4745454b]

Is the S4 mini unlocked? If it's locked to company A and you are using a sim card for company B it won't work. But it will work in the S3 mini if that phone is unlocked or allows Company B.

Or the S4 mini is broken. Or you put the tray in backwards. Or ...

 

[hardys77]

Is the S4 mini unlocked? If it's locked to company A and you are using a sim card for company B it won't work. But it will work in the S3 mini if that phone is unlocked or allows Company B.

Or the S4 mini is broken. Or you put the tray in backwards. Or ...

It's unlocked. And the sim that was on s4 at first was working but after I switched them it just wont recognize the sim anymore.