Phone's been reading 'searching' for hours.

Hi

Try a reboot press the power button down &menu button hold both down until you see apple logo this can take 30 seconds.

But if you have water damage iPhone internal part will have started to corroid

Make an appointment at Apple store they may offer you An out of warranty replacement but you will need to pay part of the cost.

But you may be better buying a newer iPhone iPhone 6s is a good iPhone.

Cheers

Brian

Hey there!

It sounds like your phone is constantly searching for a cellular signal. I would use the following troubleshooting from the article named:

iPhone: Troubleshooting No Service

http://support.apple.com/kb/ts4429

If you encounter either of the above symptoms on your iPhone, follow these steps to try to resolve the issue. Test after each step.

1. Toggle airplane mode: Tap Settings > Enable Airplane Mode, wait five seconds, then turn off airplane mode.
2. Turn your iPhone off, then on again.
3. Remove the SIM card and verify that it's a valid, carrier-manufactured SIM. Also verify that it isn't damaged, worn, or modified. Then reinsert it.
4. Check for a carrier-settings update. Connect to a Wi-Fi network. Then tap Settings > General > About. If an update is available, iOS will ask you if you want to install it. If Wi-Fi isn't available, connect your device to iTunes.
5. Update your iPhone to the latest version of iOS.
6. Reset network settings by tapping Settings > General > Reset > Reset Network Settings. This will reset all network settings, including Bluetooth pairing records, Wi-Fi passwords, VPN, and APN settings.
7. Restore the iPhone.

Thank you for using Apple Support Communities.

All the best,

Sterling

None of those things have worked for me so far and it won't leave me update my phone

Tried all trouble shooting methods to no avail. Finally took it to mobile store. They said it's the internal antenna and sending me replacement next day. Hope this helps