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iPhone 7 Boot Loop with Charger Connected, hang with no charger connected.
I have an iPhone 7 that would not boot or charge.
I plugged in a good battery and the phone just stays on the apple logo and never leaves.
On DC power supply it pulls 0.146 amp and just stays there after prompt to boot.
With the new battery and the charge cord plugged in it does a quick boot loop.
So my first thought was to change Tristar and so I did but while cutting away the heat shield
I noticed that I knocked a component off its pad. Well I was super shaky trying to put it back
and I made a mess of the area but I got it all put back but I am afraid I may have had too much
heat on the board for too long. When I hook the phone up to the DC power supply it pulls
1.48V and the max of 2.0 amps I have it set too and the short is on VDD_MAIN. I have looked
over this side with a fine tooth comb and took off every chip that had VDD_MAIN going to it
and testing for the short on the line after removing each chip with no success. The front side
of the board shows very little stuff in the area of Tristar with VDD_MAIN going to it. The only
traces of heat are Q2101 and M2800. I took off and reballed Q2101 and checked VCC_MAIN
before returning it but was still short. So I am assuming both chips are getting hot because of
their many connections to VCC_MAIN. I don't really want to take off M2800 because I am unsure
of the best way. Any ideas on the original issue and the current issue? Please / Thanks
I haven't had any micro-soldering repairs come in in a while and I was just too shaky I guess,
horrible and sloppy work compared to what I usually expect from myself.
I have not checked the front under the shields. The one chip (M2800) I mentioned is on the front though that is getting warm. But there was very little on the front with VDD_MAIN in the area I was working on the board at on the other side. This issue did not appear until after the Tristar replacement. But there is no VDD_MAIN under tristar. But I did disturb quite a bit south of Tristar.