Chosen Solution
A customer brought in an iphone 7 plus that was thrown against a wall. it had a bad lcd but could still see that the phone wouldnt boot past apple logo. now that i have the screen replaced it still stuck at apple logo and im trying to figure it out. customer has data backed up on icloud so 1st thing i tried was to restore/update in itunes. unfortunately i got error 9 every time. also if the phones off and i plug in the charger it will draw .8 amp until i unplug the charger and plug it back in. then no amp draw. im thinking tristar is the problem but not sure because there in physical damage on the heatshield of the board, where it got some small dents from the screws that clip into the frame of the screen. but its not near tristar. ill add some pics of the damage i can see.
Error 9 is usually related to bad cables. Considering the phone was physically damaged, it could be a problem with the charge port or the Tristar circuit. I wouldn’t rely too much on visual cues to determine logic board damage. That kind of physical impact can create all kinds of broken solder connections pretty much anywhere on the board. It may have many problems beyond what you are currently seeing. You’ll need to remove the shields to inspect and probe it. You may want to warn the customer and also prepare yourself mentally for a rabbit-hole.
Have you reballed anything yet? First try to replacing the tristar, if that doesn’t work try reballing the NAND and if that fails Reball the CPU.
