Reason 1: The iPhone needs a forced restart.
Your iPhone might just be frozen temporarily and requires a manual restart or a "forced restart". Please follow these steps to do a forced restart.
Reason 2: The battery is completely drained.
If your battery has run out completely, even when you connect your iPhone to a charger, it won't turn on immediately. Keep it charging for 30 minutes and then try to turn it on again.
Reason 3: The charging port or the charging plug is dirty.
If your iPhone still can't be turned on after charging for 30 minutes, check whether the charging port or the charging plug is covered with dirt. If the charging port is blocked by dirt, it can prevent the charging process from completing. Please try to use a cotton swab dipped in a little alcohol to remove the dirt carefully. After it air-dries,it is better to use a different charging cable. Or you can also try wireless charging.
Reason 4: Battery failure or charging port failure.
If your iPhone still can't be charged, it is suspected that there is a problem with the battery or the charging port.
Replace a battery that has been charged partially to see if the iPhone can be turned on. If it still can't be turned on, it is suspected that there is a problem with the power button or the motherboard. If it can be turned on, plug in the charger and see if it can be charged sucessfully. If the phone prompts that it is charging, it means the Lightning port is working. There is a high possibility that your battery is faulty. If it doesn't charge, please replace the charging port.
Reason 5: Power button failure.
If you doubt that the power button is not working properly, charge your iPhone first and then see whether it can turn on by itself or not . If the phone turns on and has power, there might be a problem with the power button or the connecting cable of the power button. Test the power button and replace it if necessary.
Reason 6: Display failure.
Sometimes, it might be a problem with the screen. The simplest way is turning on the phone and listen for any sounds. Or toggle the mute switch up and down to see if the phone vibrates. If there are sounds and vibrations, we can conclude that there is a problem with the screen.
Reason 7: Motherboard failure.
unluckily,if none of the above methods work, we can determine that there is a problem with the motherboard. We need to replace the motherboard. please replace the entire motherboard, or repair the faulty chip . it is better to go to the professional repair store to fix it .However if you are the maintenance enthusiasts with professional skills, just do it !
