Nokia 5110 can't see network

when I use an Orange sim card everything is ok, but once I change it to another network provider my phone just doesn't see a network, just a blank screen with no reception line, what may be the problem and how do I solve it.

Thanks

Nokia 5110 NSE-1 v5.30

The 5110 is not a dual band phone so my guess is you are using a sim from a network not supported by the phone or the sim card is faulty.