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REFERENCE iPhone XR No power (shorted PP_VDD_MAIN line)

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techikitzz

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Joined
Oct 31, 2022
Messages
22
Issue:
1. No power
2. Not charging

Solution:
1: Removed shorted capacitor related and connected to PP_VDD_MAIN line (C4902)

Reference used:
1. Phone board for bitmap (pang locate ng line)
2. Borneo for schematic diagram (pang determine ng value and role of component)

Diagnosis Procedure:
1. Test battery terminal using multimeter. Normal resistance reading sa positive line means ok ang PP_VBATT_VCC rail.
2. Plug in to DC bench at 4.1V. Reading without switching on is more than 2A. (High current)
3. Tested the PP_VDD_BOOST line using C4998 near the FPC connectors para d muna magbaklas. (good)
4. Tested the PPD_VDD_MAIN line using TP0540 near the FPC connectors para d ulit muna magbaklas. (shorted)

Maintenance Procedure:
1. Applied rosin method on VDD line outside board shields. Baka sakali hindi na kailanganin magbaklas. No luck.
2. Remove the metal shields and locate the PP_VDD_MAIN line.
3. Apply rosin/freeze spray to components connected to PP_VDD_MAIN line.
4. Inject 1.8V using short killer
5. Locate the shorted capacitor and remove it. (Hindi ko na nireplace since nakaseries naman).
6. Error ko dito, natamaan ko ung katabing maliit na capacitor pag sungkit pero naibalik pa naman. Makikita sa picture.
7. Plug in to DC bench and switch on. Nabuhay sa wakas at normal na ren ang boot current reading.
8. Done

Salamat sa Dios. More power to Pinoytechnician team!
 

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Issue:
1. No power
2. Not charging

Solution:
1: Removed shorted capacitor related and connected to PP_VDD_MAIN line (C4902)

Reference used:
1. Phone board for bitmap (pang locate ng line)
2. Borneo for schematic diagram (pang determine ng value and role of component)

Diagnosis Procedure:
1. Test battery terminal using multimeter. Normal resistance reading sa positive line means ok ang PP_VBATT_VCC rail.
2. Plug in to DC bench at 4.1V. Reading without switching on is more than 2A. (High current)
3. Tested the PP_VDD_BOOST line using C4998 near the FPC connectors para d muna magbaklas. (good)
4. Tested the PPD_VDD_MAIN line using TP0540 near the FPC connectors para d ulit muna magbaklas. (shorted)

Maintenance Procedure:
1. Applied rosin method on VDD line outside board shields. Baka sakali hindi na kailanganin magbaklas. No luck.
2. Remove the metal shields and locate the PP_VDD_MAIN line.
3. Apply rosin/freeze spray to components connected to PP_VDD_MAIN line.
4. Inject 1.8V using short killer
5. Locate the shorted capacitor and remove it. (Hindi ko na nireplace since nakaseries naman).
6. Error ko dito, natamaan ko ung katabing maliit na capacitor pag sungkit pero naibalik pa naman. Makikita sa picture.
7. Plug in to DC bench and switch on. Nabuhay sa wakas at normal na ren ang boot current reading.
8. Done

Salamat sa Dios. More power to Pinoytechnician team!
Galing saan mo ma recommend mag training idol
 
Galing saan mo ma recommend mag training idol
Salamat po. Lahat po ng training ay mahalaga. Kung ano ang makita nyong available dito po at sa group page enroll lang po kyo. Kahit gaano kasimple at kahirap ang matutunan naten basta meron ok po lahat yan pag pinagsama sama. :)
 
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