Some users of Samsung Galaxy S4 have found issues on the SIM function, LTE calls, random reboots and downloading of files. Fortunately, there are solutions to resolve them before resorting to a technician.
Reports have been sent to the DroidGuy about Galaxy S4's problems including undetected SIM card, unable to make LTE calls, random reboots, downloading errors and won't turn on.
SIM Card Not Found
An error message will appear displaying that no SIM is found on the device. It may also happen later on to users who have working SIM cards. In rare cases, the problem is usually caused by the SIM card itself.
1. Check the SIM tray if the SIM card has been placed properly. A small image is embedded near the tray on how a user should insert a SIM card.
2. SIM card itself is expired, corrupted or simply broken. Replacing it is possible but may take some business days depending on territory and network provider.
Unable to Call on 3G or 4G
Galaxy S4 won't allow the user to make 3G or 4G calls for undiscovered reasons. It is usually affected by network strength and configuration.
1. For 4G, set the network mode to 4G by going to the Settings menu or contacting the network provider.
2. For 2G and 3G, make sure that the signal strength is high which can be affected by the locations of both parties on the line.
3. If there is no signal for several minutes, turn on the Airplane Mode then switch it off or reboot the device to regain network strength.
4. In rare cases, a third-party app that affects call function may have caused the glitch.
Unusual reboot from time to time after updating to a new OS version. It can be caused by an app or the firmware installation itself.
1. Perform a factory reset to remove any application which may have caused the problem.
2. Perform a full wipe on the device. Go into Recovery Mode then select "wipe data/factory reset" and "wipe cache partition."
3. ODIN flash tool may also be a solution by reinstalling the firmware manually.
Downloading apps may not be prevented if there is no space left on the Galaxy S4. Apps are usually installed inside the internal storage rather than straight to the microSD card except on selected apps which require additional files online such as games with more than 50 MB in size.
1. Move some apps to the microSD to free up internal storage space.
2. Remove apps which are not being used anymore.
3. Transfer photos, music and video files to a computer.
Won't Turn On
One case of "won't turn on" Galaxy S4 has been reported and related to the electrical hardware property of the device.
1. Remove the battery then press and hold the Power key for one minute.
2. Put the battery back then switch on the smartphone.
3. In case it doesn't work, consult a technician to determine other hardware issues such as charging port, battery unit and others.