my sim wont work in my samsung galaxy s4 but works in other phones. & when i out other sims in my s4 they work! pls help

Solution
Is your phone, by chance, locked to a specific carrier? This can happen when your phone is locked to a different carrier, and the sim that you are trying to use not supported by your device. I would check with your carrier (that the phone came from) to find out if the phone is in fact locked. If it is, then get them to unlock it for you.

If the phone is unlocked (and you are certain of that), you can try launching the phone in "Safe Mode" to see if it accepts the sim then. If it does, then there is probably an app on the phone that is interfering with the sims installation.
Is your phone, by chance, locked to a specific carrier? This can happen when your phone is locked to a different carrier, and the sim that you are trying to use not supported by your device. I would check with your carrier (that the phone came from) to find out if the phone is in fact locked. If it is, then get them to unlock it for you.

If the phone is unlocked (and you are certain of that), you can try launching the phone in "Safe Mode" to see if it accepts the sim then. If it does, then there is probably an app on the phone that is interfering with the sims installation.
 
Solution