MacBook Pro - A1398 - No Display

[nrcslim89]

Hello, guys i have here one MacBook Pro A1398 with a logic board 820-3662-03.

This logic board won't have dGPU so it's an Intel CPU and GPU model.

I solved one issue with no Green and Orange light with help of piernov, resoldering the U7000 IC.

But now i have a second problem to try to solve...

I don't have display as well backlight on internal display.
So machine power on nice, charges well, all is in function and i have image on external HDMI port.

But i don't have internal display never... i measure and search for shorts on Backlight area but nothing seems to be in short... i don't have output backlight 55V on PPVOUT_S0_BKLT.
But theres no short and no bad aspect or look on caps... nothing is getting hot.
Already replaced the LVDS Connector as well and i know LCD Module is all fine tested on another model.

By the way i must say that is missing value on PPBUS_S0_LCDBKLT_PWR_SW

Any help or suggestions ?

Thanks to all

[ACS-Repair]

Re: MacBook Pro - A1398 - No Display

Do you know that the display is good and has worked in the past? Is the display original or a replacement? Have you tried connecting an external monitor to see if there is an output?

[Stephen]

Re: MacBook Pro - A1398 - No Display

Hello, guys i have here one MacBook Pro A1398 with a logic board 820-3662-03.

This logic board won't have dGPU so it's an Intel CPU and GPU model.

I solved one issue with no Green and Orange light with help of piernov, resoldering the U7000 IC.

But now i have a second problem to try to solve...

I don't have display as well backlight on internal display.
So machine power on nice, charges well, all is in function and i have image on external HDMI port.

But i don't have internal display never... i measure and search for shorts on Backlight area but nothing seems to be in short... i don't have output backlight 55V on PPVOUT_S0_BKLT.
But theres no short and no bad aspect or look on caps... nothing is getting hot.
Already replaced the LVDS Connector as well and i know LCD Module is all fine tested on another model.

By the way i must say that is missing value on PPBUS_S0_LCDBKLT_PWR_SW

Any help or suggestions ?

Thanks to all

What year is this in? A1398 depends on the LCD based on years.
A few things could be wrong here:
1. Bad LVDS connection on the Logic board. I would start there and test to see if you are getting voltage on any of the pins.
2. If you are getting voltage, you most likely have a bad LVDS cable on your LCD, Replacing that is fairly simple.
3. If the cable is not the culprit, the LCD may have a bad CAP. Louis Rossmann shows you how to repair these LCD models if they have a bad cap.

First and foremost I would try using another LCD of the same year for your MacBook to determine if its an LCD issue or Cable issue. In most cases it is usually a BAD cable that could go out. This happens. If your backlight fuse is not blown then you do not have a short and most likely have a bad LVDS connection if the LCD is good and cable is good. Hope this helps.