Seeing that "No SIM card detected" message on your OnePlus 13 Pro is a real roadblock. You can't make calls, send texts, or use mobile data. The good news is this is usually a simple fix, whether it's a bit of dust in the tray or a quick software refresh.
Let's start with the most common solutions that often get your connection back in under a minute.
Restart Your OnePlus 13 Pro
A simple restart clears out temporary glitches that can confuse the SIM reader. Just press and hold the power button until the power menu pops up, then tap "Restart." If your phone is completely unresponsive, you can force restart it by pressing and holding the Volume Down button and the Power button together for about 10 seconds until it vibrates and reboots.
Toggle Airplane Mode
Swipe down from the top of your screen to open the Quick Settings panel. Tap the Airplane mode icon to turn it on, wait a solid 10 seconds, and then tap it again to turn it off. This forces your phone's modem to re-establish a fresh connection with the network, which can kick a stuck SIM back into action.
Check Your SIM Card Status in Settings
It's worth a quick look to make sure the SIM hasn't been accidentally disabled in software. Open the Settings app and go to Mobile network. Tap on the SIM slot you're using (like "SIM 1") and make sure the toggle at the top for that SIM card is switched on. Sometimes an update or app can flip this off without you realizing.
Inspect and Clean the Physical SIM
If the software steps didn't work, it's time to check the hardware. First, power your OnePlus 13 Pro off completely. Find the SIM ejector tool that came in the box (a paperclip works in a pinch) and gently push it into the small hole on the SIM tray, usually on the bottom edge of the phone.
Carefully pull the tray out and remove the SIM card. Take a close look at the golden contacts on the card. If you see any dust, lint, or slight corrosion, gently wipe them with a clean, dry microfiber cloth. You can also very lightly clean the contacts inside the phone's SIM tray slot with a dry cotton swab. Blow any loose dust out of the tray before you reassemble everything.
When reinserting, make sure the SIM card is seated correctly in the tray and that the tray itself goes back in smoothly without forcing it. A misaligned tray is a common culprit.
Test the SIM in Another Device
This is the best way to figure out if the problem is with your SIM card or your phone. Pop your SIM into another unlocked phone (a friend or family member's will do). If the other phone also says "No SIM" or can't find a network, then the issue is definitely with the SIM card itself. You'll need to contact your carrier for a replacement, which they usually provide for free or a small fee.
If the SIM works perfectly in another phone, then the issue is localized to your OnePlus 13 Pro, and we can continue with more targeted fixes.
Update Your OxygenOS Software
Software bugs can interfere with modem and SIM communication. OnePlus frequently releases updates that fix these kinds of connectivity issues. To check, go to Settings > About device > OxygenOS version and tap on the "Check for update" button.
If an update is available, download and install it. I'd recommend connecting to Wi-Fi first, as these updates can be large. After the update installs and your phone restarts, check if your SIM is being detected.
Reset Your Network Settings
This is a very effective step that clears out any corrupted network configuration files without touching your personal data like photos or messages. You will have to re-enter Wi-Fi passwords and re-pair Bluetooth devices afterward.
To do this, navigate to Settings > Additional settings > Backup & reset. Tap on Reset phone, and then select Reset network settings. Confirm your choice, and your phone will reboot. Once it's back on, see if your mobile network connection returns.
Manually Select Your Network Operator
Sometimes the automatic network selection gets stuck. You can try choosing your carrier manually. Go to Settings > Mobile network. Tap on your SIM (e.g., "SIM 1") and then look for an option like Network operators or Carrier.
Tap "Search networks" and wait for the list to populate. Instead of leaving it on "Automatic," select your specific carrier's name from the list (e.g., "T-Mobile" or "Verizon"). This can establish a more stable handshake with the cell towers.
Reset Your APN Settings
The Access Point Name (APN) tells your phone how to connect to your carrier's mobile data network. If these settings are wrong, your phone might not register on the network properly, which can sometimes mimic a "No SIM" error.
In Settings > Mobile network, tap on your SIM and then look for Access Point Names. Tap the three-dot menu in the top right and select "Reset to default." This will load the standard APN settings for your inserted SIM card. After the reset, restart your phone.
Consider Switching to eSIM
The OnePlus 13 Pro supports eSIM technology. If your physical SIM card or the tray reader is giving you persistent trouble, switching to an eSIM can be a permanent solution. You'll need to contact your carrier to see if they support eSIM activation and to get the QR code or activation details. It removes the physical component from the equation entirely.
