Why is the MacBook screen blank when the display cable is connected?

Thanks, Dan! I actually put replaced the display assembly with a fully working display assembly pulled out from another MacBook A2338 but it still did not work.

@patsaquino - Did you inspect the connections? Both the main logic board and the iDP cable which connects between logic board and the T-CON board which is part of the display assembly. You may want to replace the iDP cable if you haven't you'll need to remove the logic board to get the the logic board side of the iDP cable. Reference Steps 15 ~ 17.

Hi Dan. Are the flex cables for the late 2020 M1 MBP and the 2020 M2 MBP compatible or not? I read that of the M2 is longer.

Also, I replaced the original flex cable with another and made sure that the connector on the display screen is also clean. However, nothing still appears on the screen. I connected the MBP to an external monitor and confirmed though that the Photobooth camera is working.

Thanks.

@patsaquino - There are four cables here! The backlight cable, two LCD panel cables these connect between the T-CON logic board and the main part of the lid and it’s these cables which get damaged. The last cable is the only true replaceable cable which almost never fails (just liquid damage). Seen in Steps 16 & 17 in the guide.

The original issue with the LCD cables was with the 2016 & 2017 systems when Apple made the backlight cable a bit short. The only other risk is either mechanical damage from a drop or forgetting something resting near the hing area so when you close the lid you crush it into the chin plat cutting the ribbons. That then leaves the grit issue where sand erodes the insulation exposing the copper lines shorting or just wearing them out. Sadly these three cables are not replaceable at best you might do a temporary patch but these patches just don’t hold up.

Bottom line new display assembly time.

Hi Dan. The pins on the original LCD flex cable are corroded and incomplete, so I was thinking of replacing it first before buying the whole assembly. I have a spare flex cable from an 2020 MBP M1 which I installed but did not work.

Ifixit also showed that the 2022 MBP M2 LCD flex cable is not compatible with any other MacBooks. So is this true? I read that of the M2 is longer.

Thanks again for your inputs.

Thanks, Leo. The flex cable does look a bit corroded so I'll clean it thoroughly as suggested.

No problem. Just remember to clean the motherboard side of the press connector as well.

Hi. I used a clean flex cable and the connector on the screen is also clean. However, nothing still appears on the screen. I connected the MBP to an external monitor and confirmed though that the Photobooth camera is working.

@patsaquino okay... maybe shine a flashlight onto the screen and see if it shows anything. In some cases liquid damage might lead to a nonfunctional backlight but the screen would still work.

The worst case is that the IC that manages the onboard screen is corroded or shorted, or the components that are responsible for it is corroded. With liquid damage nobody can be sure. I'd suggest taking it to a workshop and see if the technicians there can identify the problem. I only know so much about motherboards, so I can't really help much.