You may have this issue if your LG Optimus F3™ 4G LTE:
Try each of these steps if your phone doesn't turn on.
Verify that your LG Optimus F3 4G LTE has a sufficient charge.
Verify that your phone, charging port, and battery contacts are not damaged.
If your phone is damaged, do not complete the remaining steps in this guide. Contact Virgin Mobile Customer Care.
Verify that you are using a compatible charger.
You risk severe damage to your phone if the charger isn't the same voltage, amps, and plug type as your original charger. You can purchase compatible chargers on www.virginmobileusa.com.
Verify that your LG Optimus F3 4G LTE can power on.
If your phone does turn on, verify that it is running the most recent software.
If you're still having issues, contact Virgin Mobile Customer Care.