To fix a muffled microphone issue on your Samsung Galaxy S22: (1) Ensure that there is no physical obstruction covering the microphone, such as a phone case or dirt. (2) Clean the microphone gently with a soft brush or compressed air to remove any debris or dust. (3) Check for any software updates for your device and install them if available, as updates often include bug fixes and improvements. (4) Restart your phone to refresh the system and potentially resolve any temporary glitches affecting the microphone. (5) Test the microphone in different apps and scenarios to determine if the issue persists universally or is specific to certain applications. (6) If the problem continues, consider resetting your phone's settings to default. Backup your data before performing this step. (7) If none of the above solutions work, contact Samsung customer support or visit a service center for further assistance or to determine if there is a hardware issue with the microphone.

To fix a black screen issue on Xiaomi Mi Note 10: (1) Perform a forced restart by pressing and holding the power button for about 10-15 seconds until the device restarts. (2) If the issue persists, ensure the device has sufficient battery charge or connect it to a power source. (3) Try booting into Safe Mode by pressing and holding the power button, then long-pressing "Power off" until prompted to enter Safe Mode. If the screen works in Safe Mode, an app might be causing the issue. (4) If the problem persists, consider factory resetting the device through recovery mode. Backup your data before performing this step. (5) If none of the above solutions work, contact Xiaomi customer support or visit a service center for further assistance.