What to do if unlocked AT&T Galaxy S9 won’t work with MetroPCS network

Hello Android fans. Today’s #GalaxyS9 troubleshooting article will address some text messaging and networking issues. We hope you’ll find this post helpful.

Problem #1: Dual SIM Galaxy S9 Plus keeps showing “The SIM card has locked” error

Hi, I bought a new Galaxy S9+ here in Hungary (Europe), and i wanted to use it with 2 SIM card, because i live half-halt time in the EU and in the USA. The 1. SIM is a local Hungarian card, and the 2. SIM is USA card. I totally turned OFF the USA SIM in the the SIM card setting menu, so i use here in Hungary only the local SIM card. The phone runing with hungarian language, but time to time appear on the screen this error message in a white window, in English language: “The network did not respond in time. The SIM card has locked. Please power cycle the device and if the problem persist contact Customer Service”. In the white window the error message in English, but also have an OK and a cancel text inside, but the cancel in hungarian languange like this “MEGSE”. I have to change this new phone to an other one in the store, because this phone is wrong, or all Samsung S9+ is the same and all has this error? Thank you.

Solution: When it comes to an issue like this, the most probable reason is coding-related. In other words, your phone’s network programming is either incompatible with the SIM card or network services it’s working on. To see if the issue can be fixed on your end, try doing two things:

Network settings reset
Factory reset

Force reboot your S9

Before doing the two resets, we highly recommend that you restart your S9 Plus. instead of doing the regular restart, you want to do a forced reboot. To do this, just press and hold the Power and Volume Down keys together for 10 seconds and wait until it reboots. After the procedure, observe the device if it still reboots. If so, move on to the next step.

Network settings reset

If a Galaxy S9 Plus device encounters text messaging or internet connection issues, clearing its current network configuration may help. The following changes will occur by performing a Reset of network settings.

Stored Wi-Fi networks will be deleted.
Paired Bluetooth devices will be deleted.
Background data sync settings will be turned on.
Data restrictive settings in applications that were manually turned on/off by the customer will be reset to the default setting.
Network selection mode will be set to automatic.

If you haven’t tried it yet, follow the steps below:

From the Home screen, swipe up on an empty spot to open the Apps tray.
Tap General Management > Reset > Reset network settings.
Tap Reset settings.
If you have set up a PIN, enter it.
Tap Reset settings. Once complete a confirmation window will appear.

Factory reset

Should nothing change after resetting the network settings, try wiping the phone so all software information will be returned to their defaults. Factory reset will delete all your photos, videos, contacts, etc. Be sure to back them up ahead of time. You can use Samsung Smart Switch to do that.

To factory reset your Galaxy S9 Plus:

Back up data on the internal memory. If you have signed into a Samsung account on the device, you have activated Anti-theft and will need your Samsung credentials to finish the master reset.
Turn off the device.
Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
When the green Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).
Press the Volume down key several times to highlight ‘wipe data / factory reset’.
Press Power button to select.
Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
Press Power button to select and start the master reset.
When the master reset is complete, ‘Reboot system now’ is highlighted.
Press the Power key to restart the device.

Contact your network operator

Should both solutions won’t help, contact your network operator in Hungary to see if there’s anything that they can do to help. There may be an issue with their SIM card to not work properly with the particular Galaxy S9 model you’re using.

Problem #2: Galaxy S9 keeps showing delayed sent text messages

When using the Samsung messaging app on my phone my sent text messages show on the sent screen late. Not too late, but at least 5 seconds late. It’s been like this since I’ve first bought my S9+. I believe the recipient receives the message on time, it just doesn’t show on my sent screen as soon as its sent. It bugs me! I was just wondering if that’s how its suppose to be?

Solution: There must be a bug within the text messaging app itself. Try wiping its cache and data first and see if that will help. Here’s how to do that:

Create a backup of your text messages.
Open Settings app.
Tap Apps.
Tap on More settings at the upper right (three-dot icon).
Select Show system apps.
Find and tap your app.
Tap Storage.
Tap Clear Data button.
Restart your S9 and check for the problem.

If the issue persists, factory reset your device and see what happens. As far as our own experience is concerned, this is not supposed to happen. If wiping the messaging app’s data won’t help, factory reset might. Refer to the steps above to know how to factory reset your S9.

Problem #3: What to do if unlocked AT&T Galaxy S9 won’t work with MetroPCS network

Hello Droid Guy. I just got a Samsung Galaxy S9 and am attempting to unlock the phone. I contacted AT&T and received the unlock code. Their instructions state: 1. Turn off your Galaxy. 2. Take the AT&T SIM out of the slot. 3. Insert the SIM from the other wireless carrier. 4. Power the phone back on. 5. When the phone prompts, provide the unlock code that you received from AT&T. 6. Complete the remaining setup process by following the displayed instructions. 7. Start using your Galaxy normally.

When I power the phone back on with my MetroPCS SIM, I don’t see any prompt for an unlock code. There is a message that says something like “#MM08 phone is not allowed.” Do you know what’s going on here? I appreciate any help you can provide. Best regards, Andrew C. Andrew

Solution: We don’t work for AT&T so we have no direct knowledge what this particular error means. It may be an AT&T-only code that only their technicians can interpret. A quick Google search for that particular error also did not yield any result. We suggest that you ask AT&T about it to get first hand information.

Keep in mind that unlocking a device does not mean it can work with any network.

Depending on the current MetroPCS service in your area, they may be using CDMA or GSM technology. Because AT&T is a GSM network, there’s a chance that it may not be compatible with the type of network technology MetroPCS is using in your area (they both have CDMA and GSM networks).

Another possible reason why no unlock screen pops up is because your phone’s hardware is not compatible with MetroPCS network. Carrier-branded smartphones, like the one you have from AT&T, can only run on specific radio frequencies. These frequencies are determined by a hardware in the phone. So, if your S9’s frequency does not match that of MetroPCS, it won’t be able to communicate with the tower at all, even after you insert the SIM card. Try doing some research about your phone’s radio frequencies by using the correct phone model. Then, once you have the list of frequencies that your phone is designed to work on, compare that to the frequencies of MetroPCS in your area (you may need to contact MetroPCS for this information or do some research on Google). If your phone’s frequencies do not that of MetroPCS, you’re out of luck as it means you are never going to use it in that network.