Be sure to test your device after completing every step, to see if the problem is already solved. Otherwise, continue to the next step/method.
Start here whenever you're ready.Step 1. Verify and make sure you're within range of your network or within your network carrier's coverage area. One of the possible causes as to why you will have no service or get no signal on your device is because you are out of coverage area. So, it's a good start to check on this matter first, before jumping further to troubleshoot network problems.
Step 2. Check and make sure the SIM card is properly placed or inserted in the device. This is recommended especially if you start to have this problem after you've done something on your device that could possibly dislocate the SIM card.
Here is the proper way to remove/insert the SIM card on your Note 3 device:
a. Be sure the completely power off the device. You should never attempt to remove the SIM card while the device is powered on because doing so may cause damage to the SIM card and/or the device itself.
b. Position the device with the display (screen) facing away.
c. Locate the notch in the cover located in the upper left corner, then pull the cover off gently.
d. Locate the notch in the bottom right corner of the battery, then pull the battery out gently.
e. Now slide the SIM card out of the slot. After a few seconds, re-insert the SIM card into the slot.
f. Carefully align the battery contacts. Once everything is properly aligned, press the battery into position.
g. Finally, align the cover and press it gently into place.
Step 3. Make sure the Airplane Mode is disabled or turned off. Please note that the device will not be able to make or receive phone calls or use any data services while the Airplane or Standalone mode is enabled or turned on. Follow these steps to disable Airplane mode on your Note 3:
a. Press and momentarily hold the Power button until you see the Phone options screen shows. Do this while the phone is powered on.
b. When you're already prompted with the Phone options screen, select Airplane mode. The Airplane mode is an off/on option so if you see it's on, turn it off to disable the feature.
Step 4. After you ensure the Airplane mode is off and yet the problem continues to exist, perform a soft reset. The process is similar to restarting a desktop computer. It is often one of the first methods to troubleshoot a device without affecting data unless the battery is apparently very low. Follow these steps to perform a soft reset on your Galaxy Note 3:
a. Press and hold the Power button.
b. Select Restart from the phone options.
c. Select OK.
If you cannot perform a soft reset with the aforesaid steps, the simply remove and re-insert the battery and that should do the same.
If all else failed to resolve the problem on your Galaxy Note 3, then it's either you go for a hard reset, which will reset your device to factory default with all your personal information removed or deleted from your device. Otherwise, you may contact your network carrier and escalate your network issue with them.
Contacting of your ISP is especially important when you've just encounter a no signal or no service problem on your Galaxy Note 3. There is a possibility that the network problem you are having is due to a network outage affecting your service or it could be due to a problem on your account status. So, better contact them first for further assistance and recommendations.