Apple released the slimmed-down, buffed up iPad Air on November 1, 2013 in a choice of Space Gray or Silver. It packs the custom A7 processor and ships in 16, 32, 64, and 128 GB configurations.

299 Questions View all

Ipad Air wont charging and turn on

Charger connected when not show any screen, not reponse

I checked rails

PP3V0_S2R_TRISTAR : 0v

PP1V8_S2R_TRISTAR : 0v

PPVBUS_PROT : 4.4v

Ppvbus e75 usb conn : 4.4v

Help me please

Sorry I cannot speak english well

Update (03/07/2017)

Block Image

Block Image

Block Image

Block Image

Block Image

Block Image

Block Image

I checked VCC MAIN

VCC MAIN : ALL 5.2V, NOT SHORT

and PP3V0_S2R_TRISTAR , PP1V8_S2R_TRISTAR line

Block Image

checked

but all capacitor not short, volatage is 0

upload several pictures,

check please

Answered! View the answer I have this problem too

Is this a good question?

Score 0

Comments:

Add

WLED LX A,B : 5.2V (datasheet :20v)

PPLED OUT A,B : 5.2V (datasheet :20v)

PPLED OUT BACK REG : 5.2V(datasheet :20v)

Measured value is lower than the value of the Regulation

U8100 problem?

by

Replace the tristar. It is very chipped and probable damaged.

by

Check if the WLED and PPLED lines are shorted to vcc_main.

by

Add a comment

2 Answers

Chosen Solution

The TRISTAR voltages should not read 0V.

Those voltages are being driven by the PMIC (U8100). You will need to determine if the 0V, probably caused by a short somewhere along the line, is due to a faulty PMIC, faulty Tristar (U6000) or a bad capacitor along the line.

UPDATE (2017-03-07)

I saw your update on the measured voltages. It would appear that the LED Buck Converter is not doing its job. This is caused by either defective passive components, such as the coil and diode (these are easy to check), or it is a defective PMIC. Considering you have other voltage issues (i.e. Tristar), I would lean more towards the PMIC. However, given that the PMIC is much harder to replace, you could try changing Tristar first to see if that solves the problem.

I would also probe all of the output voltages on the PMIC to see if there are more problems.

Was this answer helpful?

Score 4

Comments:

Thank you for your kind reply. "What is mean I,E? I'll check it.

by

Add a comment

Are those going into or coming out of the tristar? Test for vccmain, and short to ground on those pins. Also will it power up with a known good battery?

Was this answer helpful?

Score 1

Comments:

Thank you for your kind reply.

I'll check it.

by

Add a comment

Add your answer

Chulsunpark will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 2

Past 30 Days: 10

All Time: 40