iPhone 5S apparently dead

Question

iPhone 5s

Apple iPhone 5s는 2013년 9월 10일에 발표되었습니다. 수리는 이전 모델과 유사하며 스크류 드라이버 및 비집는 도구가 필요합니다. GSM 또는 CDMA / 16, 32, 또는 64GB / 은색, 금색 및 스페이스 그레이.

3531 질문 전체 보기

John Dupont @johndupont

평판: 95

5

3

게시일: 2019년 6월 16일

옵션

iPhone 5S apparently dead

my iPhone 5s’ screen was damaged.

I changed it, together with the backside plastic parts at the top and bottom.

Since then it won’t turn back on. It is even not detected by iTunes.

I have made the following measurements with battery connected and USB port connected to power outlet:

PP_BATT_VCC: 0V
- measured between TP2 and a screwhole
PP5V0_USB_CONN: 0V
- measured between TP1 and a screwhole

I haven’t found any test point for PP_VCC_MAIN.

Would anyone have a clue as to where the problem lies, and how to move forward?

답변되었습니다! 답변 보기 저도 같은 문제를 겪고 있습니다

좋은 질문 입니까?

예 아니요

점수 0

댓글 달기

답변 1개

선택된 답변

Minho @refectio

평판: 221.4k

Refectio - Mail-in Micro-Soldering Repairs & Data Recovery

15

289

806

게시일: 2019년 6월 16일

옵션

First, not all screw holes are connected to ground. Use the SIM reader as that is easily accessible and connected to ground.

Second, seeing as how this follows a screen replacement, I would double check my work and insure there are no damaged flexes (screen) and that the connectors and surrounding area did not sustain any damage or debris. The iPhone 5S is prone to developing Long-Screw Damage (LSD). This occurs when the screws for the LCD retaining bracket are mixed up and a long screw goes where a short one should be. This damages the pcb and cuts traces that pass directly underneath the standoff.

I would also re-install the original screen to see if that makes a difference as low cost/quality screens can be problematic.

If the screen makes no difference, then you most likely damaged something on the logic board. Continue your probing and if the 0V persists on VCC_MAIN, then you have a short somewhere that needs to be found. Depending on your skill level, you could either hunt it down yourself using the schematic and boardview or have it looked at by a reputable shop that does micro-soldering work.

해당 답변은 도움이 되었습니까?

예 아니요

점수 3

댓글 2개:

Thanks for the swift and friendly reply!

I tested for continuity between the battery connector’s ground pin and the screw hole, and I had it, so I guess that screw hole is connected to ground.

Thanks for sharing about Long Screw Damage. How can I test for that?

I think I tried with the old screen, and got the same result, but I’ll check again.

Do you have any hint as to how I can find the short? Just check for continuity with ground at different places?

Thanks again for your help!

John Dupont 의 2019년 6월 18일

Here's an interesting link for LSD.

As for finding shorts, using freeze spray can be helpful. However not all shorts leave a heat signature, especially if you are using a current-limiting DCPS.

Minho 의 2019년 6월 18일

댓글 달기

Thanks for the swift and friendly reply!

I tested for continuity between the battery connector’s ground pin and the screw hole, and I had it, so I guess that screw hole is connected to ground.

Thanks for sharing about Long Screw Damage. How can I test for that?

I think I tried with the old screen, and got the same result, but I’ll check again.

Do you have any hint as to how I can find the short? Just check for continuity with ground at different places?

Thanks again for your help! — John Dupont
Here's an interesting link for LSD.

As for finding shorts, using freeze spray can be helpful. However not all shorts leave a heat signature, especially if you are using a current-limiting DCPS. — Minho

iPhone 5s

iPhone 5S apparently dead

답변 1개

귀하의 답변을 추가하세요