My son really did a number on his iPhone 4. The front and back glass were cracked into pieces. The
charging port barely made enough contact to charge the battery. And since there were so many cracks in the front and rear glass, water found it's way in. Water damaged the logic board, the charging dock no longer intermittently worked, the rear camera was full of water and the phone would no longer illuminate. It had a black screen and I could barely see anything unless I used a flashlight to view. And the home button wasn't functioning at all (while using a flashlight to view apps)
The parts that I purchased from iFixit were either original, seemingly factory OEM. High Quality. I fixed the phone. Unfortunately, damage to the logic board was the main culprit. I should of known all along.
Throw $ at an iPhone 4? Probably not a good idea but I had to complete the repair! It was a good learning experience. I will purchase repair components from iFixit when necessary in the future.