I recently fixed a MacBook Pro Retina Mid 2012 (A1398) which had a bad screen flicker. The display would randomly glitch and produce artifacts in random locations on the screen. I haven't had any screen flickers or glitches since.
At first I believed it was the Vcore chip, U8900, but I had already re-soldered the chip and the glitches persisted. After further research, I believe it is caused by the Wi-Fi antenna interfering with the display signals.
If anyone is able to perform this solution and it doesn't work, I'll gladly edit or remove this post as to not waste anyone else's time.
Symptoms
- Internet speed test causes the screen to flicker
- Turning off Wi-Fi, changing the Wi-Fi channel, or using a 5Ghz network alleviates the issue
- The screen flickers during bootup
- The screen flickers regardless of the graphics processor selected
- External display works fine
See the reference section for an example of the screen flicker.
If your screen is turning completely off or the device is kernel panicking, see the Vcore fix in the reference section.
Solution
The proposed solution is to better shield the signal traces and flex cables at the LCD from the Wi-Fi and Bluetooth antennas.
Obligatory disclaimer: I am not liable for damaged devices or any other property. Perform this repair at your own risk.
Supplies
- Screwdriver kit
- Precision tweezers
- Copper foil tape (with conductive adhesive)
Follow any repair guide to remove the screen from the chassis. See the reference section for some examples.
1. Remove the bottom cover
2. Unplug the battery connector
3. Unplug the three uFL antenna connectors and the webcam connector
4. Unscrew and remove the hinge covers on both sides
5. Unplug the display connector
6. Fully open the laptop and remove the 6 screws securing the display brackets
7. Rotate the display slightly to detach it from the chassis
Next you’ll need to partially disassemble the display:
8. Remove the clutch cover end caps using precision tweezers. They tend to break, so take your time. They have a locking post, a little bit of adhesive, and pull straight out (try not to twist them)
9. Slide the clutch cover to the right and remove.
10. Remove the tape securing the display cable to the antenna array
11. Unscrew the hinge holding the display cable
12. Unscrew and set aside the antenna array
13. Disconnect and remove the display cable from the LCD controller
Apply the copper foil tape to the entirety of the LCD controller, over the flex cables, and partially onto the aluminum. Make a cutout on the tape for the display cable connector to ensure that the left-most flex cable receives shielding.
![display_connector.jpg]( "display_connector.jpg")
Ensure good contact to the PCB using the back of your finger nail, a spudger, or credit card to smooth out the tape.
![applied_copper_tape.jpg]( "applied_copper_tape.jpg")
Examine how the antenna array locks to the display. Carefully slice open the copper tape near the flex cables (Do not damage the flex cables) to allow the existing shielding on the antenna array to lock into place.
Ensure that there are no possible shorts on the display connector and the smaller connector next to it.
The copper tape should be thin enough for the screws holding the antenna array down to puncture through and screw in as normal.
Optionally, apply some copper tape to the clutch cover to shield the display cable. Do not cover any antenna traces.
![clutch_cover.jpg]( "clutch_cover.jpg")
Finally, reassemble and test the laptop for any flickering.
References
Flicker Example: www.youtube.com/watch?v=VcexXDC0dlc
Display Removal: www.ifixit.com/Guide/MacBook+Pro+15-Inch+Retina+Display+Mid+2012+Display+Assembly+Replacement/9708
Clutch Cover Removal: www.ifixit.com/Answers/View/231623/How+do+I+replace+the+hinge-clutch+cover
Display Disassembly: www.youtube.com/watch?v=7oPhdNlJTdI
Vcore Repair: www.youtube.com/watch?v=zWR-smvDPZ4
Display Teardown: bunkai.biz/en/mac/A1398_2013_lcd.html
Relevant Article: news.softpedia.com/news/How-to-Fix-Flickering-Display-on-MacBook-Pro-Retina-427598.shtml
Relevant Issue: www.ifixit.com/Answers/View/184610/MacBook+Pro+15%22+Retina+Mid+2012+display+flicker
At first I believed it was the Vcore chip, U8900, but I had already re-soldered the chip and the glitches persisted. After further research, I believe it is caused by the Wi-Fi antenna interfering with the display signals.
If anyone is able to perform this solution and it doesn't work, I'll gladly edit or remove this post as to not waste anyone else's time.
Symptoms
- Internet speed test causes the screen to flicker
- Turning off Wi-Fi, changing the Wi-Fi channel, or using a 5Ghz network alleviates the issue
- The screen flickers during bootup
- The screen flickers regardless of the graphics processor selected
- External display works fine
See the reference section for an example of the screen flicker.
If your screen is turning completely off or the device is kernel panicking, see the Vcore fix in the reference section.
Solution
The proposed solution is to better shield the signal traces and flex cables at the LCD from the Wi-Fi and Bluetooth antennas.
Obligatory disclaimer: I am not liable for damaged devices or any other property. Perform this repair at your own risk.
Supplies
- Screwdriver kit
- Precision tweezers
- Copper foil tape (with conductive adhesive)
Follow any repair guide to remove the screen from the chassis. See the reference section for some examples.
1. Remove the bottom cover
2. Unplug the battery connector
3. Unplug the three uFL antenna connectors and the webcam connector
4. Unscrew and remove the hinge covers on both sides
5. Unplug the display connector
6. Fully open the laptop and remove the 6 screws securing the display brackets
7. Rotate the display slightly to detach it from the chassis
Next you’ll need to partially disassemble the display:
8. Remove the clutch cover end caps using precision tweezers. They tend to break, so take your time. They have a locking post, a little bit of adhesive, and pull straight out (try not to twist them)
9. Slide the clutch cover to the right and remove.
10. Remove the tape securing the display cable to the antenna array
11. Unscrew the hinge holding the display cable
12. Unscrew and set aside the antenna array
13. Disconnect and remove the display cable from the LCD controller
Apply the copper foil tape to the entirety of the LCD controller, over the flex cables, and partially onto the aluminum. Make a cutout on the tape for the display cable connector to ensure that the left-most flex cable receives shielding.
Ensure good contact to the PCB using the back of your finger nail, a spudger, or credit card to smooth out the tape.
Examine how the antenna array locks to the display. Carefully slice open the copper tape near the flex cables (Do not damage the flex cables) to allow the existing shielding on the antenna array to lock into place.
Ensure that there are no possible shorts on the display connector and the smaller connector next to it.
The copper tape should be thin enough for the screws holding the antenna array down to puncture through and screw in as normal.
Optionally, apply some copper tape to the clutch cover to shield the display cable. Do not cover any antenna traces.
Finally, reassemble and test the laptop for any flickering.
References
Flicker Example: www.youtube.com/watch?v=VcexXDC0dlc
Display Removal: www.ifixit.com/Guide/MacBook+Pro+15-Inch+Retina+Display+Mid+2012+Display+Assembly+Replacement/9708
Clutch Cover Removal: www.ifixit.com/Answers/View/231623/How+do+I+replace+the+hinge-clutch+cover
Display Disassembly: www.youtube.com/watch?v=7oPhdNlJTdI
Vcore Repair: www.youtube.com/watch?v=zWR-smvDPZ4
Display Teardown: bunkai.biz/en/mac/A1398_2013_lcd.html
Relevant Article: news.softpedia.com/news/How-to-Fix-Flickering-Display-on-MacBook-Pro-Retina-427598.shtml
Relevant Issue: www.ifixit.com/Answers/View/184610/MacBook+Pro+15%22+Retina+Mid+2012+display+flicker
