Why can't I get a signal any more?

Maybe you should buy a new phone.

Sometimes the issue may lie with your cell phone’s SIM card and its connection to the phone itself. A cheap trick for troubleshooting that connection is to take a pencil eraser and to rub the SIM card’s copper/gold terminals (remove the SIM card from the socket of the cell phone first of course!)

Rub gently to remove oxidation or other accumulation (dust). Then reinsert the SIM card and check the contact points with where it connects to the phone (if possible). It may also be possible to “exercise” that connection if your SIM card sits inside a slot or tray-bottom line, an improperly seated SIM card may affect reception. Also, I have actually had my SIM card replaced by AT&T by visiting them in-store (they shouldn’t charge you if you argue that the SIM may be faulty). This has worked for me in the past where a newer SIM card actually connected to the networked more effectively (not sure how exactly, but the service rep said it does).

Thank you sndfreQ. I did make them give me a new one. Nothing happened. Now what? (actually I’m going to do the thing with the eraser.)

Pixel, do you mean this? Like, if I had a different physical phone, the signal would pick up better? I’ve asked other people to see if their phones get a signal and they don’t – not at
my house.

If you go to a physical AT&T store, such as in a mall, they can enter your home address in their computer and show you the towers near your area and the signal strenth. They did this for me when I was dropping calls and I went in to complain. It literaly looks like a Google map with but with shaded areas that show different colors for the various signal strengths. Turned out I was in a weak area.