Hey there, sorry to hear your LG V20 is stuck in a boot loop—let’s walk through some practical fixes to get it back up and running. I’ve dealt with this exact issue on a few V20 units before, so these steps should help.

Sometimes the boot loop is just a temporary system glitch. Give this a shot first:

• Press and hold the Power button + Volume Down button for 10–15 seconds, until the screen goes completely black and the LG logo reappears.
• Let go of the buttons and wait for the phone to finish booting. This often fixes minor hangs without losing any data.

Corrupted system cache is a common culprit for boot loops. This step won’t delete your personal data, so it’s safe to try:

1. Turn off your V20 completely.
2. Press and hold Power button + Volume Up button. When you see the LG logo pop up, release the Power button but keep holding Volume Up until you enter the Recovery Mode.
3. Use the Volume keys to navigate to Wipe Cache Partition, then press the Power button to select it.
4. Select Yes to confirm, wait for the process to finish, then choose Reboot System Now.

If clearing the cache doesn’t work, a factory reset will wipe all system data and restore the phone to its original state. Note: This will delete all your photos, apps, messages, and personal files—only do this if you have a backup or have no other options.

1. Enter Recovery Mode using the same steps as above.
2. Navigate to Wipe Data/Factory Reset and select it with the Power button.
3. Choose Yes to confirm the reset, then wait for it to complete. Select Reboot System Now once done.

If your V20 was rooted, had a custom ROM installed, or the system files are severely corrupted, flashing the official stock firmware can fix the boot loop. You’ll need a Windows PC for this:

1. Install the official LG USB drivers on your computer (make sure they’re compatible with the V20).
2. Download the correct stock KDZ firmware for your V20 model (match your region and specific variant, e.g., H910, H918—using the wrong firmware can brick your phone).
3. Get the LG Flash Tool (a free utility for flashing LG firmware).
4. Put your V20 into Download Mode: Turn it off, then press and hold Volume Down button while plugging the USB cable into your PC. Release the button when you see the "Download Mode" screen.
5. Open LG Flash Tool, load your KDZ file, set the mode to Flash, and click Start.
6. Wait for the process to finish (don’t disconnect the cable or turn off the PC mid-flash). The phone will reboot automatically once done.

If all software fixes fail, the boot loop might be due to hardware problems:

• Battery Issues: The V20 has a removable battery—try replacing it with a new, genuine LG battery (old or swollen batteries can cause power delivery issues).
• Loose Connections: If you’ve opened the phone before, check if the battery connector, display cable, or motherboard connectors are properly seated.
• Hardware Failure: If none of the above works, it could be a faulty power module or motherboard. In this case, you’ll need to take it to a repair shop.

Start with the simplest fixes first (force restart, clear cache) before moving to more drastic steps like factory reset or flashing firmware. Most boot loops on the V20 are software-related, so you’ve got a good chance of fixing it without hardware repairs.

内容的提问来源于stack exchange，提问作者Victor Manzo