Seeing "No Service" or a completely empty signal bar on your Redmi Note 13 Pro can stop you in your tracks. It means your phone can't find your carrier's network for calls, texts, or mobile data. The good news is this is almost always a software or settings issue you can fix yourself.
I'd start with the simplest fix first. Just press and hold the power button for about 15 seconds until you feel the phone vibrate and the screen goes black. Keep holding until you see the Redmi or MIUI logo appear. This force restart clears out any temporary glitches in the system that might be blocking the cellular radio.
Check Your SIM Card and Slot
Pop open the SIM tray on the bottom edge of your phone using the included ejector tool. Take out the SIM card and give the gold contacts a quick visual inspection. If you see any dust or debris, gently wipe them with a soft, dry cloth.
Make sure you're reinserting the SIM into the correct slot if your model has dual SIMs. The primary slot is usually labeled "SIM 1." Push the tray all the way back in until it clicks firmly into place. A loose connection here is a surprisingly common culprit for no service.
Disable Airplane Mode and Check Mobile Data
Swipe down from the top of your screen twice to open the full Quick Settings panel. Look for the airplane icon and make sure it's not highlighted. If it is, tap it once to turn Airplane Mode off.
While you're there, also check that mobile data is enabled. The icon looks like two arrows pointing opposite directions, often next to your carrier name. If it's off, tap it to turn it on. You can also go to Settings > SIM cards & mobile networks to verify both your SIM is enabled and mobile data is turned on for the correct line.
Manually Select Your Network Operator
Sometimes your phone gets stuck trying to connect to a weak or unavailable network tower. You can force it to search again and lock onto your proper carrier. Go to Settings > SIM cards & mobile networks.
Tap on the SIM card you're having issues with, then select Choose network. The phone will scan for a moment. When the list appears, select your carrier's name instead of leaving it on "Automatic." This direct approach often re-establishes a solid connection immediately.
Update Your Access Point Name (APN) Settings
Your APN is like the address your phone uses to find your carrier's data network. If these settings are wrong or missing, you'll have no service. Head back to Settings > SIM cards & mobile networks > [Your SIM].
Tap on Access Point Names. If the list is empty or the selected APN looks incorrect, you'll need to add the right one. The fastest way is to tap the three-dot menu and select Reset to default. If that doesn't populate it, you'll need to get the exact APN settings from your carrier's website or customer service and enter them manually.
Reset All Network Settings
This is a more thorough step that clears all your saved network configurations without touching your personal data. It will erase your Wi-Fi passwords, paired Bluetooth devices, and cellular settings, so be ready to reconnect to Wi-Fi networks afterward.
To do this, go to Settings > About phone. Tap on Reset or Factory reset (don't worry, you're not doing that full reset yet). On the reset menu, select Reset Wi-Fi, mobile & Bluetooth. Confirm your choice and enter your screen lock PIN if prompted. After the phone reboots, it will rebuild its network connections from scratch.
Use the Phone Information Menu for Diagnostics
Your Redmi Note 13 Pro has a hidden engineering menu that lets you see the exact state of the cellular radio. Open your phone dialer and type *#*#4636#*#*. This should open the "Testing" menu.
Tap on Phone information. Here, you can see if the radio is actually on. You can try toggling it off and back on using the button. Also, check the "Set preferred network type" dropdown. For the best balance, selecting NR/LTE/WCDMA/GSM is usually a good choice. Just don't change other settings in this menu if you're unsure.
Check for a Software Update
Software bugs in MIUI can occasionally affect modem performance. Xiaomi releases updates that often include stability fixes for connectivity. Plug your phone into its 67W charger to ensure it has enough battery, then go to Settings > About phone > MIUI version.
Tap the "Check for updates" button. If an update is available, download and install it. The 67W charging is great for a quick top-up during this process, but be aware the phone can get warm during both fast charging and a large software update, which is normal.
Test Your SIM Card in Another Phone
This step helps you figure out if the problem is with your Redmi Note 13 Pro or with the SIM card/service itself. If you have access to another unlocked phone, power it off and insert your SIM card.
Turn that phone on and see if it gets signal. If it also shows no service, the issue is almost certainly with your SIM card or your carrier account. In that case, you need to contact your carrier's support. They can check for outages, reprovision your line, or send you a replacement SIM card.
Consider a Factory Reset
If you've tried everything else and your SIM card works fine in another phone, a deeper software issue might be the cause. A factory reset will wipe your phone back to its original out-of-the-box state, so this is a last resort.
Make absolutely sure you have backed up all your photos, messages, and app data first. You can use Xiaomi Cloud or a local backup. Once ready, go to Settings > About phone > Factory reset. Select Erase all data and follow the prompts. After the reset, set up the phone as new and test the SIM card before restoring your backup, to see if the issue is cleared.