The list below is a general troubleshooting guide to help resolve common problems experienced by wireless internet users.
1) Restart the computer
2) Plug your 3G modem in to a different USB port.
3) Uninstall all connection manager software and any other software related to your modem. Then restart the computer and reinstall the software.
4) Remove the SIM card from the modem and wipe with a dry cloth.
5) Make sure the SIM card is inserted in the modem the correct way (this is a very common mistake!).
6) Check that any security \ firewall software (e.g. McAfee, Symantec) you have installed isn't blocking the connection. Try temporarily disabling the security \ firewall software.
7) Verify settings! APN, Username, Password etc
8) Is your computer a work computer? Has it been specially configured? Check with your IT department
9) Make sure you have the latest Windows / Mac OS updates
10) Check with the mobile operator that supplied your modem if they have released new drivers / software.
11) Check your modem hasn't been blocked! This happens when a modem has been reported stolen and the network operator has disabled it.
12) Check with the mobile operator that your SIM card has been activated
13) Call the mobile operator who supplied your SIM card to check they are not experiencing any network \ account problems.
14) Sometimes a very weak signal can give unexpected errors. If you have a laptop test your connection outside. If you are using a desktop, connect your modem to a USB cable and try putting it close to a window or higher up.
15) Has the SIM card got a security PIN enabled? Take the SIM card out of the USB modem and put it into your phone. From your phone you will be able to disable the security PIN.
16) Verify your SIM card is data enabled (3G capable). Contact the mobile operator who has supplied your SIM
17) Unexpected results can occur if your modem is not getting enough power from the USB port it's plugged into. Try a different USB Port. If it's plugged into a USB hub or Keyboard USB port try plugging it directly into your computer.
18) Does your SIM card have credit! Check with your mobile operator
19) Try a different SIM card in your modem, to see if the problem is with the SIM card or the modem.
20) Try the modem in a different computer to see if the problem is with the modem or your computer.
21) Your modem can only be accessed by one program at a time. For example, having the modem connection manager running and then trying to unlock your modem with the unlock utility will not work!