Fix Your Stuff Community Store

Repair information and guides for the iPhone 6S released by Apple on September 25, 2015. Models: A1688, A1633

2688 Questions View all

Options

6s with dead PP1V8

Hello folks,

I have a weired acting 6s here. First it came with dead. It had a short on Vcc main (C3618_F ) which I replaced. Short is gone but now the trouble starts.

First of all it looks like someone already repaired the backlight (the customer hadn’t had it repaired and just bought it used).

So the history is…it worked until they exchanged the battery to a not original one (2,1A instead if 1,8Ah).

My current measurements look as followed

DCPS on 4,2V

Vcc main = 4,2V

Vcc Batt = 4,2V

PP5V0 USB - 5V

PP3V0_Tristar - first there are 3V but then it starts jumping to 0 and to 1,7V and back to 3V but it’s never constant voltage

PP1V8 - 0V

PP3V0_Nand - jumps aswell from 3V to 0 (like PP3V0_Tristar)

PP_CPU - jumps aswell from 0,8 to 0V and so on

PP_GPU - 0V

According to my dcps there is no other short and I measured the resistances of those lines and had those results:

PP1V8 - 70kOhm

PP_CPU - 110Ohm

PP3V0_Nand - starts at around 20MOhms and goes up to 40+

PP_GPU - 30Ohm

I tested the tristar with a tristar tester and no failure found. I never had such a heavy defect on a board and I’m uncertain if this could only be caused by a defect U2000 (pmic). Since I have never heared of this one being defect.

Could anyone give me a hint on what to inspect/check or if it’s better to just let it be and trash it?


Thanks in advance

Answered! View the answer I have this problem too

Is this a good question?

Yes No
Score 0
1 Comment

Ok So after some trial and error it seems that the voltage jumps are “normal” if some line (in my case PP1V8) is not present. The U2000 sets a reset (maybe to reset erorrs or w/e) and tries to restart itself to get the line back up. But since this doesn’t fix the problem of the dead PP1V8 it does this looped and the above behavior occurs. So I guess it’s really the U2000 itself. *!&$!&$^ I thought I would get past this w/o having to try to get this one replaced. Well then, wish me good luck.

by

Add a comment

1 Answer

Filter by:
Most Helpful Newest Oldest
Chosen Solution

Options

Which Tristar tester did you use?

The voltages measured seem a little off, specifically the jumping PP3V0_Tristar and NAND and the 0V mon PP1V8. Because your original issue was related to a replacement battery, I would check the Tristar/Tigris circuits again. Have you tried measuring the voltage on the battery connector (on the logic board) with the Lightning port connected? You should measure around 3.7V.

Was this answer helpful?

Yes No
Score 1

1 Comment:

I used the tristar tester from http://tristartester.com/. The voltage on the batt connector with USB plugged in jumps aswell. I have 3,7V then it goes down to 1,7V then goes to 0 and repeats this. Basicly it's the same stuff with weired wmeasurements on the PP_Tristar etc....

by

Add a comment

Add your answer

Der Sepp will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 0

All Time: 341