Q: iPhone 4s won't make calls after IOS 8 update

Hello emcruz1995

For issues with making phone calls on your iPhone 4s, check out the General phone and connectivity issues and look at the iPhone Call and Connection assistant as well as the No cell signal strength anywhere parts to get it sorted out.  

iPhone: Hardware troubleshooting

http://support.apple.com/kb/TS2802

No cell signal strength anywhere

1      Verify that your carrier name appears in the status bar, at top left of the display.

2      Turn Airplane mode on, wait for the airplay symbol to appear in the status bar, and then turn it off again.

3      Reset Network Settings: Tap Settings > General > Reset > Reset Network Settings.

4      If your iPhone is in a case, try removing it to ensure that the case isn't interfering with the cell signal strength.

5      Contact your carrier to find out the following:

▪       If you are in an area with network coverage.

▪       If there is a network outage.

▪       The account is properly configured to your phone.

6      Try to restore your phone and set it up as new.

Note: Your iPhone may be able to receive calls in as little as 15 minutes after activation. If you are migrating your current phone number, it can take longer–up to several days, depending on the type and status of your former service account–before calls are routed to iPhone. In the meantime, you can make calls and use the device's other features.

Regards,

-Norm G.