Q: My iphone 4 does not receive any wifi signal unless its very close to the router. (please help ASAP it's really frustrating)

Hello MisterAnton,

It sounds like you are unable to connect to a Wi-Fi network unless your phone is extremely close to a router. I would use the troubleshooting from the following article to help resolve the issue, named:

iOS: Troubleshooting Wi-Fi networks and connections

http://support.apple.com/kb/TS1398

1. Tap Settings > Wi-Fi and turn Wi-Fi off and on. If your Wi-Fi setting is dimmed, follow these steps.
2. Restart your iOS device.
3. Tap Settings > Wi-Fi and locate the Wi-Fi network to which you're connected.
4. Tap and Forget this Network.
5. Try to connect to your desired Wi-Fi network.
   Note: You may need to enter your Wi-Fi password again if your network requires one.
6. Turn your Wi-Fi router off and on2. If your ISP also provides cable or phone service, check with them before attempting this step to avoid interruption of service.
7. Update your device to the latest version of software.
8. Update your Wi-Fi router to the latest firmware2. For AirPort Base Stations, install updates using the AirPort Utility.

And:

 

Wi-Fi disconnects or signal strength is less than expected

1. Move closer to the Wi-Fi router (access point).
2. Check for sources of potential interference.
3. Remove any case, stand, or other accessories from your iOS device and see if signal strength improves.
4. Reset network settings by tapping Settings > General > Reset > Reset Network Settings. Note: This will reset all network settings including
   • previously connected Wi-Fi networks and passwords
   • recently used Bluetooth accessories
   • VPN and APN settings

Thank you for using Apple Support Communities.

Cheers,

Sterling