Press and hold the power button for at least 15 seconds. Keep holding it until you see the ROG logo appear on the screen. This force restart is the quickest way to clear any temporary software glitch that's freezing the touchscreen.
I'd start with this one. It works for most unresponsive screen issues, especially if the problem started after installing a new app or a system update. Your phone should vibrate and restart, and the touch response should be back to normal.
Remove Any Screen Protector or Case
Take off your phone's case and check the screen protector. A poorly applied tempered glass protector or a case that presses on the screen's edges can interfere with the touch sensors. This is a common issue with phones that have curved screen edges or active cooling vents like the ROG Phone 9.
Peel off the screen protector completely and test the touch response with your bare finger. If the screen works perfectly without it, you'll need a higher-quality protector designed specifically for gaming phones with sensitive touch sampling rates.
Clean the Screen Thoroughly
Turn the phone off and give the screen a proper clean. Oils, sweat, and dust from gaming sessions can build up and confuse the capacitive touch layer. Use a soft, lint-free microfiber cloth slightly dampened with water.
Make sure your hands are completely dry before testing the screen again. Avoid using harsh chemicals like window cleaner, as they can damage the oleophobic coating on the display.
Check for Software Conflicts in Safe Mode
Boot your ASUS ROG Phone 9 into Safe Mode to see if a third-party app is causing the problem. First, press and hold the power button until the power menu appears. Then, tap and hold the "Power off" option on your screen.
A prompt will ask if you want to reboot to Safe Mode. Tap "OK." If your touchscreen works perfectly in Safe Mode, you have a problematic app. Start by uninstalling any recently downloaded apps, especially those that draw over other apps or control screen sensitivity.
Calibrate the Touchscreen
ASUS includes a touchscreen calibration tool in the system settings. Open the Settings app and go to System > Developer options. If you don't see Developer options, go to About phone and tap "Build number" seven times to enable it.
In Developer options, scroll down and look for "Show taps" or "Pointer location" to visualize your touch input. You can also search for "Touch sensitivity" in Settings to adjust the screen's response, which can help if you're using gloves or a different stylus.
Update Your System and Apps
An outdated version of Android or a buggy system update can cause touch issues. Connect to Wi-Fi and go to Settings > System > System update to check for the latest Android security patch or version update for your ROG Phone 9.
Also, open the Google Play Store and update all your apps. Pay special attention to gaming apps and any apps with accessibility services, as these can sometimes interfere with system-level touch functions.
Check for Overheating and Performance Settings
The Snapdragon 8 Elite chip in the ROG Phone 9 generates significant heat during long gaming sessions. Extreme heat can cause the screen or digitizer to malfunction temporarily. Let the phone cool down completely if it feels very warm.
Open the Armoury Crate app and check your performance profile. Try switching from "X Mode" or "Dynamic" to a balanced profile. Also, enable "Bypass charging" in the game settings if you play while plugged in, as this reduces heat buildup from the 65W charging system.
Perform a Factory Reset
Before you do this, ensure all your important data is backed up to your Google account or a computer. A factory reset will erase everything on the phone. You can initiate it from the Settings menu if your touchscreen is partially working: go to System > Reset options > Erase all data (factory reset).
If the screen is completely unresponsive, you can use the hardware buttons. Power off the phone, then press and hold the power button and volume down button together. When you feel a vibration, release the power button but keep holding volume down until you see the recovery menu. Use the volume buttons to navigate to "Wipe data/factory reset" and select it with the power button.