iPhone 8 Plus - Not turning on/Connecting to iTunes

Hello everyone!

I have an iPhone 8 Plus here that seems to be dead. I’m taking a look at it for a friend of mine and I would appreciate any help, assistance or advice.

A few months ago…

• She had dropped her phone and the ringer switch was dented. She used a toothpick to push it back into place and now it is fine.
• A little bit after that time, the phone would randomly start restarting. While she was using it, the screen would turn into the black “powering off” screen with the spinning spiral, and then would restart automatically.

Couple other things:

• She does use a third-party lighting cable to charger her phone
• She once did have some dust stuck in her charging port, and she used a toothpick to remove it.
• When she was last using the phone, it was somewhere between 70 - 80% battery when it randomly died.
• There are no cases of water damage, the screen is not cracked, and has not been replaced before.
• Her battery health (not battery level) was at 87-90%
• She’s had this phone for about 3-4 years.
• She uses AT&T

Here’s the problem:

• The iPhone does not turn on
  • When plugged into a charger, the phone is not responsive. Same thing with a computer, the phone does not display the apple logo, or the battery low, or charging logo. The computer also, does not recognize the phone is plugged into it. She has also tried holding the lock/power button and volume down, to try a force restart but that also did nothing. Saturday, we will try wireless charging to see if the phone decides to respond. I also have a voltage/amp reader so we’ll test any battery problems too.
• Personally, I think this may be due to a bad battery or damage to the Tristar IC chip, but I was wondering if anyone else in the community had any previous experience to this problem.

Thank you for taking the time to read through this!!

Update:

The wireless charger did nothing. The phone did not boot up. However, when i plugged the phone into a portable Anker powerbank with power IQ, the powerbank did automatically turn on, which means the phone did start taking in power.

Update #2:

Changing the battery also had no effect on the phone :(