Hi, I have a Unlocked Samsung Galaxy S3 (originally T-Mobile) that I use with Straight Talk I have a SIM card in it from the BYOP program. It is not getting any signal/service. I have verified that it's still unlocked, not blacklisted, the SIM works in my other phone as well but I ordered a new SIM anyway and that SIM works in both phones so it is not the SIM. I have done a factory reset but still nothing. I have also taken the battery out, put it back in, and turned phone on but it didn't work.. I have done all the steps that Straight Talk suggest. I also checked and I still have an IMEI number. I have done a software update. Sometimes the phone will have 4G but then seconds later it will go back to no service/signal and say searching on the unlock screen. The icon at the top is a circle with a slash through it. When I try to make a call when it has that icon it says mobile network not available. My APN settings have been updated and are correct and airplane mode is not on. I have GSM/WCDMA only selected and have tried switching to the other two but still nothing. This might not be important but my Wi-Fi does still work. My girlfriend has the same phone and has no problems getting signal. Mobile network is selected.. I have no idea what else I can try I'm getting so frustrated. Can anyone help? I am so tired of having basically a paper weight!!