Seeing "No Service" or a missing signal icon on your ASUS ROG Phone 9 can be a real headache, especially when you need to make a call or get online. This usually means your phone can't connect to your carrier's cellular network for calls, texts, or mobile data.
The good news is that most of the time, this is a temporary glitch you can fix yourself. I'd start with the simplest solutions first, as they often do the trick.
Restart Your Phone and Check Airplane Mode
First, give your ROG Phone 9 a quick restart. This clears out any temporary software bugs that might be interfering with the radio. Just press and hold the power button, then tap "Restart" on the screen.
While you're at it, swipe down from the top of the screen to open the Quick Settings panel. Make sure the Airplane Mode icon isn't highlighted. If it is, tap it once to turn it off.
It's also worth checking inside the settings. Go to Settings > Network & internet and ensure Airplane Mode is switched off there too.
Reinsert Your SIM Card
A loose or dirty SIM card is a common culprit. The ROG Phone 9 uses a nano-SIM, and the tray is on the bottom edge of the phone.
Use the SIM eject tool that came in the box (or a small paperclip) to pop out the tray. Take out the SIM card, give the gold contacts a gentle wipe with a soft, dry cloth, and then carefully reseat it. Push the tray back in until it clicks.
After you reboot the phone, give it a minute to search for the network. If you have a case on, sometimes removing it can ensure the tray is fully seated.
Check for a Carrier Service Outage
Before you dig deeper into your phone's settings, it's smart to rule out a problem on your carrier's end. Service outages can happen due to maintenance or technical issues.
You can quickly check by visiting your carrier's website or their social media accounts like X (Twitter), where they often post updates. If you have another phone on the same network handy, see if it also has no service.
You can also try calling your carrier's customer service from a different phone. They can tell you if there's a known issue in your area.
Manually Select Your Network Operator
Sometimes your phone gets stuck trying to connect to a weak or incorrect tower. You can force it to search again and pick the right one.
Go to Settings > Network & internet > Mobile network. Tap on "Network operators" or "Choose network." Your phone will search for a moment.
When the list pops up, select your carrier's name directly. If you don't see it, or if you're traveling, choose "Select automatically" instead and let the phone find the best available signal.
Verify Your APN Settings
The Access Point Name (APN) is like the gateway that lets your phone access your carrier's data network. If these settings are wrong or got corrupted, you'll lose data and sometimes voice service too.
Navigate to Settings > Network & internet > Mobile network > Access Point Names. You should see a list with at least one APN for your carrier.
If the list is empty or the settings look wrong, you'll need to enter them manually. The exact APN details are unique to your carrier. The quickest way to get them is to visit your carrier's support website and search for "APN settings" or contact their customer service.
Reset Your Network Settings
This is a more thorough step that clears all your network-related configurations back to factory defaults. It will erase saved Wi-Fi passwords, Bluetooth pairings, and your cellular settings, but it won't touch your personal photos, apps, or files.
To do this, go to Settings > System > Reset options. Tap on "Reset Wi-Fi, mobile & Bluetooth." Confirm the reset and let your phone reboot.
After it restarts, you'll need to reconnect to Wi-Fi and re-pair Bluetooth devices, but it often resolves persistent network gremlins.
Use the Phone Information Menu
Android has a hidden testing menu that lets you interact directly with the phone's radio. You can access it by opening your dialer and entering *#*#4636#*#*.
This will open the "Testing" menu. Tap on "Phone information." Here, you can see detailed status info. Look for a dropdown menu labeled "Set preferred network type."
Try selecting a different mode, like "NR/LTE/GSM/WCDMA" if it's not already chosen, then toggle the "Mobile radio power" off and back on. This forces the radio to re-initialize.
Check for a Software Update
Software bugs can sometimes affect cellular connectivity. ASUS releases updates that include stability improvements and bug fixes. It's always a good idea to make sure you're running the latest version.
Go to Settings > System > System update. Tap "Check for update." If an update is available, download and install it. Make sure your phone is connected to Wi-Fi and has a good charge, preferably over 50%, before starting.
After the update installs and your phone reboots, check if your signal has returned.
Disable Any VPN or Game Mode Features
If you use a VPN app, try disabling it temporarily. Some VPNs can interfere with how your phone routes network traffic, leading to a "No Service" state. Go to your VPN app and disconnect, or go to Settings > Network & internet > VPN to manage active connections.
Also, consider the ROG Phone's gaming features. While X Sense mode is great for performance, try switching to a standard profile like "Dynamic." In rare cases, aggressive network optimizations in game modes can affect stability.
You can find these in the Armoury Crate app. Disabling the AniMe Vision matrix display on the back can also help rule out any unusual power or software interactions, though it's a long shot.
Test with a Different SIM Card
This step helps you figure out if the problem is with your phone or with your SIM card/account. If you can, borrow a SIM card from a friend or family member who uses a different carrier.
Pop their SIM into your ROG Phone 9. If you get service with their SIM, then the issue is likely with your original SIM card or your carrier account. You'll need to contact your carrier for a replacement SIM.
If you still get "No Service" with a known-good SIM card from another network, the problem may be with your phone's hardware, like the antenna or the internal modem.
