Refer to the following article from Taimienphi.vn for detailed insights into each method of fixing the Samsung S20 power on/off problem.
Fixing Samsung S20 Power On/Off Issue
Method 1: Force restart your device
The easiest way to fix the Samsung S20 power on/off issue is to force restart the device.
Press and hold both the Power button + Volume Down button simultaneously until the device restarts.
Try using different charging accessories
Method 2: Try using a different cable
Sometimes, the issue might be due to your Samsung S20 running out of battery and the charging cable being faulty, causing the device not to power on. Try using a different charging cable and charge the battery, then power on to see if the issue persists.
Method 3: Clear cache memory via Recovery Menu
By clearing the cache memory of Samsung S20 to remove unnecessary files and help address a range of issues, including: device hang-ups, freezing, inability to power off, unresponsive screen, black screen errors, speeding up device performance, ... .
Step 1: Swipe down the notification panel, then press the Power button.
Step 3: Press and hold both the Power button + Volume Up button until the Recovery Menu appears on the screen.
Step 4: Use the Volume Down button to navigate to the Wipe cache partition option.
Step 5: Press the Power button to select the option.
Step 6: Use the Volume Down button to move and press the Power button to select Yes.
Wait until all data on the left corner of the screen is completely wiped.
Step 7: Press the Power button to restart the device.
Method 4: Perform Factory Reset
Performing a Factory Reset will wipe all your data and settings on Samsung S20. Ensure you have backed up your important data before proceeding:
Step 1: Swipe down the notification panel, find and tap the Power button.
Step 2: Tap on Power off => Power off again to turn off the device.
Step 3: Press and hold both the Power button + Volume Up button until the Recovery Menu appears on the screen.
Step 4: Use the Volume Down button to navigate to the Wipe data/factory reset option, then use the Power button to select the option.
At this point, the screen will display a notification stating that all user data will be erased, and cannot be recovered.
Step 5: Use the Volume Down button to move down to the Factory data reset option, use the Power button to select the option.
Step 6: Wait for the process to complete.
Step 7: Finally, press the Power button again to restart the device.
If you've tried all methods and your Samsung S20 still won't power on, the cause may be hardware-related. In this case, the last solution for you is to take it to reputable phone repair centers for assistance.
https://Mytour.vn/cach-sua-loi-samsung-s20-khong-bat-va-tat-nguon-duoc-27117n.aspx
This article from Mytour.vn has just guided you through some ways to fix Samsung S20 power on/off issues. Additionally, if you're facing a black screen issue on S20, refer to the article on fixing black screen issues on Samsung Galaxy S20 here.