I just got my iphone it keeps telling me network lost>>>

Here are a few troubleshooting steps you can try if your Bluetooth connection keeps dropping between your iPhone and another device:
1. Restart both devices: Turn off Bluetooth on your iPhone, restart it, and then turn Bluetooth back on. Similarly, restart the device you're trying to connect to.
2. Forget and reconnect: On your iPhone, go to Settings > Bluetooth, find the device you're connecting to, tap the "i" icon, and select "Forget This Device." Then try reconnecting from scratch.
3. Check for interference: Bluetooth connections can be affected by interference from other devices or Wi-Fi networks. Try moving away from potential sources of interference or turning off other wireless devices nearby.
4. Update software: Ensure both your iPhone and the other device have the latest software updates installed. Sometimes, updates can resolve connectivity issues.
5. Reset network settings: On your iPhone, go to Settings > General > Reset > Reset Network Settings. This will reset all network settings, including Bluetooth connections. Reconnect to the Bluetooth device afterward.
6. Battery level: Ensure that the device you're connecting to has sufficient battery power. Low battery levels can sometimes affect Bluetooth stability.
If these steps don't solve the issue, it could indicate a compatibility problem or a potential hardware issue with either your iPhone or the Bluetooth device you're trying to connect to. Consider contacting Apple Support or the manufacturer of the other device for further assistance.

• Turn off Bluetooth and restart your iPhone or iPad.
• Repair the Device you Connect: Go to Settings > Bluetooth > Choose the device you are having issues with > Tap on the info button next to the device > Tapon Forget This Device.
• Reset Network Settings: Settings > General > Reset > Reset Network Settings. You need to set up your Wi-Fi connections again after doing this.
• Try restoring your iPhone: You can restore your device from iTunes or iCloud. Bear in mind that it will erase your existed data so you'd better back up your iPhone or iPad in advance.

You can check this article to learn more about how to fix iOS 9 problems
The Most Common iOS 9 iOS 9 1 Update Problems and Solutions

Go into
Settings->Passcode->Enter your passcode->Turn Passcode Off

Try resetting:
Hold the home and power buttons at the same time until the Apple boot logo appears. No data will be lost
Next Settings > General > Reset > Reset Network Settings.

For more tutorial go through: http://jailbreakunlocknews.com/

Try to reset the network settings, go to “Settings” -> General -> Reset -> Reset Network Settings.

If the problem is not solved, try to go to your local repair store. Sometimes the problem cannot be solved. Good luck!

Just like a computer, in order to keep your Iphone working, you must clear out your cache, and cookies. On your menu, select 'Settings" then go to Safari", scroll to the bottom, Click Clear History, next clear cookies, and finally clear cache. You will notice it going a bit faster. Just like a PC, or Mac, you get a bunch of clutter on a wireless connection, it can slow your browsing, and you can even be knocked of the internet. It's good to do once a week if you use your computer a lot.

anybody know how to fix lost phone service after jailbreak?

GO TO www.iclarified.com
dre u will find instructions of a software called ultrasn0w. u will have to add the source in cydia and install a application.
that might work

Go - Settings/General/(scroll down to) Reset/Reset Network Settings.

Phone will turn itself off and on again. Et voila - no more annoying message saying "Network Lost"

Note: This procedure doesn't mess around with any of your other settings, applications etc.

Good luck.