IPhone 6s Plus pp_1v8 fluctuating from 1.8v to 0v - GSM-Forum

chapster · 10-08-2017, 01:42

Hi everyone

My 6s plus won't power on and isn't recognised by my computer.

When I check voltages, pp_1v8 is alternating between 1.8v and 0v repeatedly every second. There is no short on that rail.

If I remove the inductor so the voltage rail goes nowhere after it's produced in the PMIC, its high at over 4V which is presumably lack of load and feedback due to the inductor being out of circuit. But it stays constant; no fluctuating.

Has anyone experienced this on any voltage rail and remembers the cause?

czesk20 · 10-29-2017, 02:17

1. What resistance do you have on PP1V8 line?
2. What reading do you have in diode mode on this line?
3. What coil did you removed?

I have similar issue. I have lower than should be resistance on PP1V8 line

10-08-2017, 01:42	#1 (permalink)
chapster Insane Poster Join Date: Jul 2009 Posts: 86 Member: 1086977 Status: Offline Thanks Meter: 50	IPhone 6s Plus pp_1v8 fluctuating from 1.8v to 0v Hi everyone My 6s plus won't power on and isn't recognised by my computer. When I check voltages, pp_1v8 is alternating between 1.8v and 0v repeatedly every second. There is no short on that rail. If I remove the inductor so the voltage rail goes nowhere after it's produced in the PMIC, its high at over 4V which is presumably lack of load and feedback due to the inductor being out of circuit. But it stays constant; no fluctuating. Has anyone experienced this on any voltage rail and remembers the cause?

10-29-2017, 02:17	#2 (permalink)
czesk20 Insane Poster Join Date: Nov 2012 Posts: 78 Member: 1836029 Status: Offline Thanks Meter: 9	1. What resistance do you have on PP1V8 line? 2. What reading do you have in diode mode on this line? 3. What coil did you removed? I have similar issue. I have lower than should be resistance on PP1V8 line Last edited by czesk20; 10-29-2017 at 02:25.