Chosen Solution
I have an iPhone 6 plus phone that was not used for 6+ months. It was on, battery likely drained and then left for those 6+ months unused. I recently tried turning it on and unfortunately got no signs of life. It is dead. I suspected the battery as some research seemed to point that batteries draining completely and then being unused can cause damage. I tested it with a multi-meter and it pretty much had 0v. So I bought a new battery off eBay for really cheap (£5). It arrived after a few days, but unfortunately has not solved the issue. The phone remains dead. The battery I bought reads 0.5V on the multi-meter. This seems quite odd. Is it meant to be that low? The battery is rated for 3.82V. I also measured the voltage at the battery connector with just the charger plugged in. It reads a constant 0.8V. This also seems odd. What am I dealing with here? Is it a battery problem, or something else?
You will need to rule out a faulty charge port first but there should be around 3.8V on the battery connector with the charge cable connected. You will need to check the PP_VCC_MAIN “0.3” and PP_BATT_VCC “0.42” circuit with your multimeter in diode mode with red probe on ground. (Without power connected of course). You know where PP_BATT_VCC is and here is the location of PP_VCC_MAIN
UPDATE: Spoke to the seller that sold me the battery. They sent me a new one and the phone now turns on. It looks like it charges as well (battery percentage does go up). It still doesn’t show the apple logo without any battery connected which I find most odd. It did also start reboot looping every few minutes, but that seems to have stopped after I did some fiddling about. I’ll be monitoring the device to see if it starts rebooting again.
Put IPhone in dfu mode and use 3u tools to restore. iTunes is trash. 3u tools will do a deep flash and restore phone plus you can activate it during flash.ake sure to have an internet connection and turn of windows defender as it likes to block the firmware verification after flash.
