Chosen Solution
My friend just bring me his iPhone 6s Plus and it completely dead and I check the charging port ok and lcd is good and try power it with another full charge battery nothing happen. So I try to check short with multimeter I can see a very little short and when I connect USB cable to the charging port and measure the voltage in battery connectors it 4.5 and drop to 0.25 to 1.25 then 4.5 then 2.5 not stable can any one help me where should I start
It’s the tristar. Gonna go ahead and guess it’s from over use with an aftermarket charger cord, which the person blew the first battery, and then left it on the charger to continually use it, and the tristar has now failed. If you have experience with microsoldering, then this is a good answer, if not send it to a board repair shop. Many of them have a mail in service
