Seeing that "No SIM" or "SIM card not detected" message on your POCO X7 Pro is a real roadblock. You can't make calls, send texts, or use mobile data. The good news is that with HyperOS 2, most of these issues are caused by simple glitches you can fix yourself in a few minutes.
I'd start with the quickest solutions first. They often clear up temporary software hiccups that cause the phone to lose sight of the SIM card.
Restart Your POCO X7 Pro
It sounds too simple, but a restart clears the phone's temporary memory and can fix a surprising number of issues. Just press and hold the Power button, then tap "Restart" when the menu pops up.
If the phone is completely unresponsive, you can force a restart. Press and hold the Power button for about 15 seconds until you feel a vibration and see the POCO logo appear on screen.
Toggle Airplane Mode On and Off
Swipe down from the top of your screen to open the Quick Settings panel. Look for the airplane icon and tap it to turn Airplane Mode on.
Wait about 10 seconds, then tap the icon again to turn it off. This forces your phone's modem to reconnect to the network from scratch, which can often kick-start a stuck SIM detection.
Check the SIM Card is Enabled in Settings
Sometimes, a software update or a random bug can toggle the SIM off in the settings. Open your Settings app and go to Mobile network.
You should see your SIM card listed there. Make sure the toggle switch next to it is turned on. If you're using dual SIMs, check that the correct one is set as your default for calls and data.
Clean and Reinsert the SIM Card
If the software steps don't work, it's time to check the physical connection. Power your POCO X7 Pro off completely first. Find the SIM ejector tool that came in the box (a small metal pin).
Insert it into the tiny hole on the SIM tray, usually on the bottom edge of the phone. Gently pull the tray out and carefully remove the SIM card.
Look at the gold contacts on the SIM. If you see any dust, lint, or slight discoloration, gently wipe them with a clean, dry microfiber cloth. You can also very lightly blow into the SIM tray slot to dislodge any debris. Reinsert the SIM, making sure it's seated correctly in the tray, and push the tray back in until it clicks.
Test Your SIM Card in Another Phone
This is the best way to figure out if the problem is with your SIM or the phone itself. If you have access to another unlocked phone, power it off and insert your POCO's SIM card.
Turn that phone on. If it also shows "No SIM" or fails to get a signal, the issue is almost certainly with the SIM card itself. In that case, you'll need to contact your mobile carrier for a replacement.
If the SIM works perfectly in the other phone, then the issue lies with your POCO X7 Pro, and we can continue with more specific software fixes.
Update Your Phone's Software
Outdated software can have bugs that affect network connectivity. POCO regularly releases updates for HyperOS that include stability improvements.
Go to Settings > About phone > HyperOS version. Tap on "Check for updates." If an update is available, download and install it. It's a good idea to be connected to Wi-Fi and have your phone charged above 50% before starting.
Reset Your Network Settings
This is a very effective step for network-related issues. It will reset all Wi-Fi, mobile data, and Bluetooth connections to their factory defaults, but it won't touch your personal photos, messages, or apps.
To do this, open Settings and scroll to Additional settings. Tap on Back up and reset, then select Reset phone. Here, choose Reset network settings and confirm. Your phone will reboot, and you'll need to reconnect to Wi-Fi networks and re-pair Bluetooth devices.
Check and Reset APN Settings
APN (Access Point Name) settings are like an address that tells your phone how to connect to your carrier's internet. If these are wrong, you might see a "No SIM" or "Emergency calls only" message.
Go to Settings > Mobile network > SIM card settings. Select your SIM and look for Access Point Names or APN. Tap the three dots in the top right and select "Reset to default."
If that doesn't work, you may need to enter the settings manually. Your carrier's website or customer service can provide the correct APN details for your plan.
Try Manual Network Selection
By default, your phone automatically chooses the strongest network. Sometimes this process can get stuck. You can manually select your carrier to force a connection.
Navigate to Settings > Mobile network > SIM card settings. Tap on Network operators. Turn off the "Select automatically" option. Your phone will search for available networks.
When the list appears, select your specific carrier's name (e.g., Vodafone, Airtel, Jio). Wait a moment to see if it successfully registers.
Clear Cache for SIM-Related Services
Corrupted cache data in system services can cause odd behavior. Go to Settings > Apps > Manage apps. Tap the three-dot menu and select "Show system apps."
Scroll through the list and look for apps like "SIM Toolkit," "Phone Services," or "Carrier Services." Tap on each one, go to Storage usage, and tap "Clear cache." Do not select "Clear data" unless you're sure, as that may reset things to a deeper level.