This is the 25th segment of our running Galaxy S4 Problems and Solutions series. Ten problems were addressed in this post so if you have issues with your phone right now, you may want to browse this post and see if your issue is one of the things we addressed here. If no, try the first 24 parts by visiting our Samsung Galaxy S4 Troubleshooting page so you’ll have the list of all issues already published in this site.
For those who are currently bugged by a problem or two, feel free to email us at firstname.lastname@example.org and we will do our best to respond through posts like this. Please include all important details of the problem(s) so that we’ll know where to start and how to fix them.
Unlocked Galaxy S4 reads ‘No SIM’
Q: South Africa and purchased a prepaid SIM from MTN. When I put the SIM in my phone the phone reads “No SIM.” I used the SIM in an international phone and it works fine. Verizon cannot tell me what is going on. To further confuse things I just bought my son a Galaxy S5 and the SIM seems to work in the S5. Is there anything I can do to figure out why my s4 will not read this SIM? Thank you. — Gary
A: I hope you understand that we are left to assume what happened to the phone since we cannot physically check. But since the error message says “No SIM” and you have tested the SIM card using another phone, the problem must be in the phone. The “No SIM” error displays when the phone cannot detect, in any way, a SIM card. If it were a network problem, the error message must be different. The immediate troubleshooting step to take is to inspect if there’ something that in the SIM card slot of your phone that prevents the phone from properly detecting the card. If the receptors look fine then have the phone checked by a technician. If you were thinking that may be the phone wasn’t unlock, then you should be getting “Not Registered On Network” error.
Galaxy S4 stuck in boot mode
Q: I bought this phone and it was stuck in boot mode, I took it to someone and they put new software on it, it worked for two days the battery went dead and now it says system software not authorized by att. Top left screen in red system fail kernel. Any help would greatly be appreciated. I’m not a genius but I can’t afford to pay someone again and can follow directions if you can lead me in the right direction. Thank you in advance, Kim.
A: Perhaps KNOX was running in your device prior to the flashing of the new firmware or the phone has secured boot but either way, the only workaround I know would work is to flash the previous version of firmware. You can do so by using the Odin flashing tool but first you need to know the version of the previous firmware and download it to your computer.
Galaxy S4 can’t make calls over LTE
Q: Hey I bought my galaxy in February of this year, I had a iphone 4 before. Every since I have had my s4 I can have all my bars and my 4G lte will be working fine and then I try to make a call and lose all my bars and the 4G lte and the call fails. I have heard it could be defective bc my husband has the htc one and he has no problem. Thanks so much, Summer.
A: It could be a network problem. Try switching from 4G to 3G. I’m sure that would let you make calls. For more information about this problem, call your service provider.
Tap the Menu key and then tap Settings.
Tap Connections then tap More networks.
Tap on Mobile networks.
Tap on Network Mode.
Choose between 2G/3G auto or 2G/3G/4G auto.
Galaxy S4 plays audio that’s not on the list
Q: Hi. I recently did an upgrade to 4.4.2 on S4 and ever since some alarm goes off at random times with the Samsung theme song… no special time… it just goes off and is not associated with any notification that I can find. I deleted the song but its still happening… (song does not show up in any song list). To turn it off I have to press middle button device and close all apps usually this works but sometimes it doesn’t… help. Thanks much. — Beatrix
A: Apparently, you don’t know what app causes this and where that audio track is located. I’m not even sure if it’s an app the cause the problem or not. But I’m pretty sure the phone cannot play an audio that doesn’t exist in either its internal memory or external storage. Since the problem happened after the update, it’s safe to assume the new firmware messed up with the settings. I’m sorry but the best thing we could do is assume simply because of lack of information and I think factory reset would be able to fix this problem.
Galaxy S4 reboots after the update
Q: My Samsung Galaxy S4 (I9505) worked well with 4.4.2 Kit Kat. But about a week ago I updated it with Kies to a new version (baseband version I9505XXUGNE5) which includes new Knox and Kids Mode. Now, the phone is restarting several times a day but everything else works fine. What is the problem, and is there any way to get back to previous baseband version? Help please, this is very annoying.
A: First of all, determine whether the cause of the reboot is an app or not. If it’s an app, then disable or uninstall it just to find out if the problem is fixed. However, if it’s a firmware issue, wiping the cache partition may help or even factory reset. As to your question whether you can roll back to previous baseband, well, the answer is yes but you’ll have to manually flash that previous firmware using the flashing tool known to many as Odin.
Galaxy S4 can’t download apps, memory is full
Q: Greetings, my S4 keeps indicating that there’s a SD “full flag” set and I should continue downloads manually. I have moved files offline to make 2+gigs of space on the SD card and internal storage as well but I still get the message. doesn’t seem to inhibit downloading but is quite annoying. Help me loose this notification or reset the “flag.” Thanks.
A: I have encountered this problem many times already and I can tell you it’s a problem with the internal memory, not the microSD card. There’s nothing more you can do when this happens but move third-party apps to the external memory. If that doesn’t work, then something has to give in; uninstall the not so important apps, transfer your photos, videos and music to your computer until space is enough to cater the needs of apps you want to download.
Galaxy S4 now says No SIM card
Q: Hello, I own a galaxy s4 for less than a year, it started to tell me a no SIM card inserted message, once or twice a day. In the beginning, I was able to restart the phone and it will go away. now, I struggle with this restarting phone, over and over for a very long time in order to get this no SIM card error message to go away. Finally, the no SIM card error came on again, and this time, no matter how many times I restart the phone, this error message would not go away. I can’t use my phone to call anymore, very frustrated. I am wondering if you know of this issue, and how to solve it. Thanks. — Andrew
A: Apparently, it’s a SIM card issue. Best thing to do is call your service provider and have them replace your SIM with a new one, however, you will have to wait at least 5 business days before you can receive the replacement card. If you are in a country that allows SIM card to be distributed freely and phones are often unlock out of the box, then buying a new SIM card would solve the problem regardless whether you can retain your old phone number or not. Again, the most helpful party you can call for this kind of problem is your service provider.
Galaxy S4 won’t turn on
Q: Hello, I have been cruising around your blog and thought i should send you an email since I have a big headache caused by my S4. I bought my phone when I was in Korea (mistake no. 1) and I came back to New Zealand. For 3 months, it was working fine without any problem. However, one day my alarm didn’t go off and I was late to work. When I woke up I was about to check what time it was but the screen won’t turn on while the phone is on. I could see the green light flashing.
Ever since, after locking my phone screen, the screen won’t turn back on when I press home or turn on/off button. I had to take the battery out and re-start my phone again each time. And now it doesn’t even turn on when I change the battery. I have tried with new batteries and someone else’s charger but the phone still won’t turn on and I cannot fix my phone in New Zealand since my warranty only applies in the country of purchase.
I don’t know what to do… Please if you know of any solution that might bring my phone alive. Please let me know. — Chris
A: I know this may sound crazy but try to remove the battery and press and hold the power button for a minute. Place the battery back and turn the phone on. I’ve encountered a lot of times already that a problem like this can be fixed by discharging stored electricity of the capacitors.
If that will not work, then bring your phone to a technician because I’m thinking it could be a problem with the USB charging port, the component that serves as a gateway for electricity either from the charger or battery.
Galaxy S4 call problems
Q: Hello, I was hoping you may be able to help me with a current issue. When I get incoming calls I answer them but although the phone gets connected the caller gets an engaged signal. I normally have to call them back. Also when I make calls they do not always get through. Any suggestions please. Regards, Peter.
A: The thing about this kind of problem is that we are always left to assume the network is fine but what makes it even more complicated is when the party that gets disconnected or has issues is a third-party; we cannot vouch how good their coverage or network is. But it seems to me that this is more of a network problem than hardware, although, I’m not saying the phone doesn’t have issues.
My point is, call your service provider and inquire about the quality of service they offer in your area and whether there were network interruptions during the time you encountered the problem. If it’s not a network problem, then it must be the phone. Bring it in and have it checked by your provider’s technicians.
Galaxy S4 mobile data turns on by itself
Q: Hi The Droid Guy, I’ve started to get a peculiar problem since the update to Knox and the new kids mode update, I switch off WiFi and mobile data before I sleep, but for some strange reason, when my alarm goes off in the morning and I check my phone, mobile data is switched on. With the phone being synced and the full charge of the battery draining after I’ve charged it the night before. Help please. Anil.
A: Make sure all syncs, especially those that automatically syncs, are turned off or disabled. Sync is one possibility why mobile data turns on by itself. If the master sync is off and the problem still happens, try to restrict your apps from using background data. Another possibility is third-party apps. There could be an app that uses mobile data to pull updates from the server. If you don’t know which app causes it, perform factory reset.
Engage with us
Feel free to send us your questions, suggestions and problems you’ve encountered while using your Android phone. We support every Android that is available in the market today. And don’t worry, we won’t charge you a single penny for your emails. Email us via email@example.com any time. We read every email but can’t guarantee a response. Lastly, if we were able to help you, please help us spread the word by sharing our posts with your friends or visit our Troubleshooting Page. Thanks.