Dead iPhone 6 tried everything to repair suspect CPU
I have bought a broken iphone 6 from eBay to learn micro soldering and repairs. It is all going well but this device came to me and has been worked on before. Many of the capacitors have been ripped off the board, mainly on VCC_MAIN.
I found the main fault which was a shorted PP1V8_SDRAM, the short was caused by a faulty PMIC which has been replaced. When connected to a bench PSU the phone at power on draws around 45mA and does not boot. I have checked the following and they're all OK.
PP1V8_SDRAM 1.8V CPU
PP1V2_SDRAM 1.2V CPU
PP0V95_FIXED_SOC 0.95V CPU
PP1V8 1.8V CPU
Does anyone else have any ideas? Not sure what the next signal should be to the CPU to boot? I think it may be a dead or broken CPU :-( Do I need to replace all of the missing CAPs.... no long screw damage either.....everything else looks good.
Any help very much appreciated for someone learning.... loving the challenging though.....
Is this a good question?