Fixing the 30-Second Sleep Time Bug on Huawei P9 Lite after Android 7 Update

After updating your Huawei P9 Lite to Android 7, you might encounter a frustrating issue where the sleep time is automatically set to 30 seconds and cannot be changed. Here are some troubleshooting steps to help you resolve this issue:

Step 1: Check Your Settings

The first step is to verify if the sleep time option is accessible:

Go to the Settings Display Sleep option. Ensure that you are trying to change the sleep time from this menu. Sometimes, the option may be restricted due to battery saver settings.

Step 2: Evaluate Battery Optimization Settings

Battery optimizations might interfere with certain features including the display sleep timer. Check the following:

Go to Settings Battery App launch and see if there are any restrictions on the display settings.

Step 3: Boot into Safe Mode

Safe mode can help identify if a third-party app is causing the issue:

To enter Safe mode, press and hold the power button until the power off menu appears, then press and hold the 'Clear Cache' button to enter safe mode.

Step 4: Clear Cache Partition

If the issue persists, try clearing the cache partition:

Power off the device. Press and hold the Volume Up and Power buttons simultaneously until the Huawei logo appears. Use the volume buttons to navigate to 'Clear Cache Partition' and select it.

Step 5: Perform a Factory Data Reset

If none of the above steps resolve the issue, consider a factory data reset:

Back up your data first to avoid losing any important information. Navigate to Settings System Reset Factory data reset and follow the on-screen instructions to reset the device.

Step 6: Check for Software Updates

Lastly, ensure that you have the latest software updates installed:

Go to Settings System Software update to check for any additional updates that might fix the bug.

Additional Troubleshooting for Custom ROM Installation

If you installed a custom Android 7.x.x ROM using a custom recovery, you may encounter similar issues with the display sleep timer. Here are additional steps to try:

Boot your device into recovery mode. Select Wipe Advanced Wipe and then select the /cache and Dalvik directories. After wiping both, reboot the system. Try adjusting the display sleep timer again to a preset greater than 30 seconds. If the bug persists, reboot into recovery mode again, reinstall the custom ROM, and wipe the /cache and Dalvik-ART directories. Reboot the system to see if the issue is resolved.

If the issue still persists after trying these steps, contact Huawei support for further assistance.