iPad 7/8/9

Problem Description	Symptoms	Solution	Source
Not charging, no power.		- If you have a tristar tester or lightning breakout board you should test that before attempting the following. - Test with a known good battery. - Replace charge port. - If the above didn’t help you likely have a dead tristar.	Source
No power.	- Passes tristar test. - May or may not show any signs of life. - No shorts present on the power rail. - Does not automatically boot into DFU. - May or may not give error 4013 when trying to restore.	These models are notorious for CPU issues. The board flexes over time and causes the solder balls under the CPU to crack. Sometimes reflowing can be enough to fix it but it’s highly likely you’ll have to either reball or replace the CPU.	Source
No power.	- Passes tristar test. - Cycles between 0.08A to 0.30A - Backlight may flash on and off when attempting to power on.	Caused by a bad PMIC failing to output GPIO_PMU_TO_LCD_PWREN. Replacing the PMIC will solve the issue.	Source
No touch.	- Still no touch even after a digitizer replacement.	- Replace Touch mosfet. - Replace Touch IC - If the above do not fix the issue then the only other known cause of this issue is caused by a poor connection between the CPU and PCB that causes the SPI_GRAPE_SCLK signal to be missing. The solution is to pull and reball the CPU.	Source