iPhone 12 mini, 12, 12 Pro and 12 Pro Max
| Problem |
Solution
|
| No Power
|
First thing to check is the 5G antenna that wraps around the frame.
Liquid can easily reach where the flex & the 5G module plug in, causing a VDD MAIN short.
Unplug it & check for corrosion.
Here's a video example of this scenario: https://youtu.be/flsO4yW3nSQ
|
| Display black, but touch (somewhat) works. Phone makes charging sounds
|
This is caused by a faulty OLED screen. The device was dropped (likely on the front) which killed the screen. It’s a very common issue with this model. If you look closely at the screen, there are probably “bubbles” or “dots” in it. Changing the screen will fix this issue.
The screen does not need to be cracked for this issue to occur! The phone can look brand new but may still happen after a drop. You may have luck with bringing it to Apple (under warranty or consumer law) and telling them the screen stopped working.
If you are reading this after the device is out of warranty, take a look at iFixit.com to find a complete guide on how to change the screen yourself.
- iPhone 12 mini screen repair guide
- iPhone 12 screen repair guide
- iPhone 12 Pro screen repair guide
- iPhone 12 Pro Max screen repair guide
Note: iPhone 12 and 12 Pro use the exact same display panel.
|
| Screen stays super dim once it gets to the home screen. |
Symptoms:
- Phone shows Apple logo at full brightness
- Once it gets to the home screen, the display gets really dark
- Some may confuse this as "no backlight"
Solution:
- Connect the ear speaker flex to get the brightness to work
- If it still does not work, then maybe the original ear speaker flex is bad
- So in this case, try a new ear speaker flex (but you will lose Face ID)
Here's a video explanation: https://youtu.be/ShqQwVfsBcU
|
| Bootlooping
Error 4013
|
Symptoms:
- Shows apple logo for about 5 seconds, then blank, then apple logo, then blank
- Sometimes it shows a green flash for a second
- If you try to flash an update or restore, it fails right away with an Error 4013
- If you flash on 3u tools, it fails at 19%
Solution:
Flex Cables:
- Step 1 in this case is always unplug all the flex cables.
- Ideally test the board with known good Screen, Battery & Charging Port.
- If it boots, then one of your flexes is the cause.
- 99% of the time, it is the ear speaker flex. The Flood Illuminator and/or the ALS has liquid damage.
- The ear speaker flex is paired to the logic board for Face ID.
- If you want to keep Face ID, you'll need to repair the flex. If Face ID is not important, then you can just replace the flex.
- To repair the flex, you'll have to desolder the component & clean out all the corrosion, then place them back.
- If the corrosion is too severe & it damaged the flex, then you'll need to swap the Flood Illuminator and ALS to a new flex, otherwise, you'll lose Face ID.
- In some cases, another flex can cause this issue like a bad charging port.
- In this case, just replace the flex
Please Note: If the phone is stuck in Recovery Mode because it failed at the Error 4013, you have 2 options
- Kick the device out of Recovery Mode using 3U Tools. In the main screen of 3U Tools, you'll see a button that says "Exit Recovery Mode"
- You can attempt another update or restore.
Assuming you fixed the root cause of the bootlooping issue, the above 2 options should get you a working phone.
If it still fails at 4013 or still bootloops, then you haven't solve the issue.
|
FPC Connectors diode mode readings[edit | edit source]
Use these diode mode maps as a guide to troubleshoot a problem. You must use the RED PROBE on ground and the BLACK PROBE on the pin you are measuring.
For example: you are troubleshooting a no backlight situation, so you probe the pins on the display FPC that correspond to backlight. If a pin says you should read 0.65 and you are reading OL or a short to GND then that's where you need to go.
If instead of getting 0.65 you read 0.58, move on to the next one, remember every multimeter is different and even slight differences in temperature affect this readings. What you are looking for is extreme differences in values, if you are expecting some value and you get a short to ground that is where it is more likely to be your issue.
Display connector (J11500)[edit | edit source]
Diode mode for iPhone 12 Pro Display connector. Pin 1 goes towards top left, pointing to front camera cluster.
Diode mode for iPhone 12 Pro Display connector. Pin 1 goes towards top left, pointing to front camera cluster.
Charge port / dockflex Connector (J11200)[edit | edit source]
iPhone 12 Pro DockFlex charge port connector. Pin 1 goes towards top left, pointing to front camera cluster.
Battery connector (J10000)[edit | edit source]
iPhone 12 Pro battery connector. Pin 1 goes towards top left, pointing to front camera cluster.
Rear camera Connectors (J10400 & J10500 & J10600)[edit | edit source]
iPhone 12 Pro rear cameras connectors. For J10400 Pin 1 goes towards top left, pointing to front camera cluster.
iPhone 12 Pro rear cameras connectors. For J10500 Pin 1 goes towards top left, pointing to front camera cluster.
iPhone 12 Pro rear camera conector for J10600 Pin 1 goes towards top right, pointing to rear camera cluster.
Front front flex connector (J11000)[edit | edit source]
iPhone 12 Pro front flex connector. Contains the Flood Illuminator proximity sensor, ambient light sensor, earspeaker. Pin 1 goes to top right, pointing to the rear camera cluster.
Front camera connector (J10700)[edit | edit source]
iPhone 12 Pro front camera connector. Pin 1 goes to top right, pointing to the rear camera cluster.
Dot Projector connector (J10900)[edit | edit source]
iPhone 12 Pro Dot Projector, responsible for FaceID. Pin 1 goes to top right, pointing to the rear camera cluster.
IR camera connector (J10800)[edit | edit source]
iPhone 12 Pro IR camera, responsible for FaceID. Pin 1 goes to top right, pointing to the rear camera cluster.
iPhone 12 Pro upper antenna connector. Pin 1 goes to top right, pointing to the rear camera cluster.
iPhone 12 Pro upper antenna connector. Pin 1 goes to bottom right, pointing to the bottom loudspeaker.
iPhone 12 Pro SIM card reader. Pin 1 goes to top right, pointing to the rear camera cluster.
iPhone 12 Pro lower antenna connector. Pin 1 goes to top right, pointing to the rear camera cluster.
Power button connector (J10100)[edit | edit source]
iPhone 12 Pro power button connector. Pin 1 goes to top right, pointing to the rear camera cluster.
Flash and rear mic connector (J11100)[edit | edit source]
iPhone 12 Pro flash and rear microphone connector. Pin 1 goes to top right, pointing to the rear camera cluster.
