Samsung Galaxy S4 Error - SIM Card Removed - Unable to detect your SIM card.

Since you have already tried a factory reset and replacing the SIM card, I would say that this is definitely a hardware problem. You could try cleaning the contacts on both your SIM card and phone SIM slot a VERY SMALL amount of rubbing alcohol on a qtip, but I can't actually recommend this, as you could end up making everything worse. If this doesn't fix the problem, you are probably out of luck. When I had a GS4, I had the same issue and never found a good fix that wasn't replacing my device. And I wasn't even running KitKat yet at that point. Despite the lack of a recall, I believe this is a manufacturer's defect present in some GS4 devices.

My S4 was doing the same thing. Followed all the above steps and it didn't help(new sim card, soft reset, full reset). I had read on line in other forums to try and put a "shim" on top of the sim card to tighten it up in the slot.That didn't help either. Also read of people replacing the sim card tray and having no luck either(I didn't do that!).

Called Samsung and they went through all of the above steps again with no luck. They finally had me send it in and they replaced the main board under warranty(I was just under 1 year).

I haven't had any problems since(been about 9 months now).

Hi @sspiers

I’d be happy to help with the SIM error you’ve been encountering! It appears you have completed wuite a lot of troubleshooting steps for this issue. It certainly does sound like a possible device hardware issue, though the reboot fix is interesting. If it is indeed a software based issue, I would second what has been recommended by Samsung. Please try following the steps posted to enable Safe Mode to determine if the same issue occurs.

The final troubleshooting step for a software issue would be to back up the device and perform a factory reset. Samsung Kies 3 is perfect for quickly backing up and restoring your device. To perform the factory reset, see the steps listed here.

Thanks!

Charise

I believe this to be a problem between an app or a number of apps, Android and the AT&T network.

I had this problem on my Samsung GS4 SHG-i337 very intermittently under 4.2.2.  It really began to manifest itself under 4.4.2 and became really bad (3 - 10 times daily) under 4.4.4.

I have changed my SIM card and have reseated it several times.  Now I have fixed tow thicknesses of clear Scotch office tape to the back of the SIM card.  The SIM is now very tight in its holder.  I am almost certain this is not a SIM card contact problem.

What I believe is happening is this, many apps need network connectivity from time to time.  This is a random event when regarded from a user standpoint.  If the network is in a state of flux i.e. it has just suffered a micro-interruption and is in the process of just coming up or just going down AND any app needs connectivity, it may be that the SIM reports as not being available.  Android then tells the app there is a failure and Android then reports SIM unavailability.

I have re-booted my phone many times, I have run it in Safe Mode and I have re-flashed it back to 4.4.2.  The fewer 3rd party apps it use (email, calendar, etc.) the fewer faults I have.  Even with only stock apps in Safe Mode, the fault never goes away.

My phone is now out of warranty so AT&T will not help other than providing a new SIM card.

Obviously I cannot prove what I think but I have trawled the web and have been provately investigating this problem for a few months now.  It is not restricted to Samsung GS4s.  Just Google "SIM card removed Unable to detect your SIM card" to learn the extent of this problem.

I do not blame any app, Google (Android), AT&T or Samsung for this but I do think that the last three players in this list need to put their heads together and find a fix as soon as possible.

Furthwer to my previous post I would like to add that it seems that the worse the network coverage then the more likely this problem seems to manifest itself.  Again, I intend no ctriticsm of AT&T here but it's just that some places have stogner signals than others.  It would seem that where I live is not a great signal strength area and when I am at home, I seem to see the error:

"SIM card removed Unable to detect your SIM card. Your device will restart to check for your SIM card."

more  frequently.  Following a conversation with one of my neighbors who also has a GS4, he confims that he too sees this contition mainly at his home.

I have now reduced the number of apps on my phone and I have stuck to the stock apps for email and calendar.  I have reduced but not eliminated this nasty error to about twice per day.

It would be very nice if AT&T and others could look into this anomaly.

I hope that my small input will be well recieved and helpful.

My wife has her SGH-I337 with Android 4.4.4 on AT&T getting the "no SIM detected message" with a known new working SIM and a newly replaced SIM + microSD card reader installed. 
I used the SIM from her S4 in my S4 and it's working, verified.
She took it to the local AT&T Store and a new SIM was installed, it worked for about 2 days then back to the same problem
Did the hard reset procedure, and also booted this S4 into safe mode, and still the "no SIM is detected" message is appearing. Visited local AT&T Store 3x about this, called support a few time as well, now they are telling me to go talk to Samsung about this issue.....
This S4 can read microSD well. Display is working well, WiFi is good, GPS, Blutooth,  all buttons, contacts look good inside, just reading SIM is the problem.
Please let me know if you have any ideas or suggestions to get this SGH-I337 back on the AT&T network. Reading this is a common problem on the Galaxy S4 phones. This phone is 1.5 years old and in great shape otherwise. Any thoughts will Samsung issue a recall on these S4's with KitKat if enough customers complain about this issue?

I started having this problem a few days ago.  Only once or twice then pretty much regularly.  Every morning when I wake up I have the SIM card message, and it happened once while I was on a call.  I use my phone a lot for work, so that's no good.  

After searching the web and trying the piece of paper to wedge the SIM card in a little tighter (no luck), I resolved that I'd just have to get a new phone.  Then I remembered I'd been having wonking things happen with my transparent clock and weather widget for quite a while.  I'd unistalled, reinstalled, updated etc.  It had been working fine recently, but it still remains suspect.  I totally uninstalled it this morning and I haven't had the message since.  Now, the two may be totally unrelated, but I wanted to pass it along in case it does solve the problem and this could benefit someone else.