I recently bought an S4, Verizon model, and was having issues with it powering on and off. It would reboot randomly so I contacted Samsung and sent it in for repair. They replaced the PBA and sent it back. Before I power it back up I wonder if I should replace the SIM card that I originally used. I don't know if it even makes a difference. The SIM was used previously for 2 years in my Galaxy Nexus. Any thoughts or suggestions, thanks in advance.