Making sure you have a working phone is certainly important, but there's a bit more on this that we'd still need to know. It is also important to mention that your phone should always be powered off when removing or installing a SIM card. Does the phone show up as compatible when you check the IMEI here: https://www.verizonwireless.com/checkesn/ . Have you done a factory reset on the phone since installing the Verizon SIM? Did you confirm with the previous carrier that your phone is unlocked from them?