Macbook А1706 820-00239-A

nicerepairs

New member
QUOTE (I lost access to my other account, that's why I quote this here, sorry) :

"I have this really weird problem.

Screen is 90% black (from bottom to top, only top bar is visible). I changed it with another from a donor but there was some dimmed and almost black lines on top. I tested his original display on another Macbook and it works perfectly fine, so I thought maybe it was a LCD cable issue. I assembled it back but screen doesn't turn on at all. I tried with the replacement one (with the dimmed spots) and it doesn't turn either.

Currently it doesn't light up with both of the displays. It has picture on external monitor, so I know it's booting.

Any idea what to look for?"

YOUR ADVICE:

Do you get 3V3/5V_S0SW_LCD?
Check also DP_INT_HPD.

Diode mode to ground at pins 1 & 3 of J8500?

OUR RESULT ON THE TEST:

3V3/5V_S0SW_LCD is NOT present.
DP_INT_HPD is low level 0V.
Pin 1 is NOT present. Pin 3 is present.

Additional measurements we did:

VDD Pin 1 is present. Pin 2 EDP_Panel_PWR_EN is NOT present - 0V.
I've done SMC Reset and NVRAM reset.
Also update, it now doesn't even boot on external monitor... Please help. Really important Macbook.

Thanks!
 

2informaticos

Administrator
Staff member
"Pin 1 is NOT present. Pin 3 is present."
Clarify this, please.
Pins 1 & 3 of J8500 MUST give almost same reading in diode mode.

You should try to boot the board alone now, out of chassis.
Do you get voltage on CPU coils?
 

2informaticos

Administrator
Staff member
"0.220V on Pin 3."
Is that diode mode reading?
If yes, don't post the end "V"; avoid confusion with voltage reading.

"0V on Pin 1"
You should get same reading as pin 3.
However, 0.220 in diode mode is lower than expected.
Considering "OL" (if is the case) on pin 1 at same time, CPU eDP output is fried.
 

nicerepairs

New member
Yes, sorry for misunderstanding.

In diode mode.
Pin 1 and Pin 3 show different (Tested on another board, it's 0.534L on both). This one, Pin 1 is 0L, Pin 3 is 0.250L... Anything I can do if CPU eDP is fried? Reflow or anything?

Information on this Macbook is super important. Any way I can extract it if fixing it is impossible?
 

2informaticos

Administrator
Staff member
Test external video disconnecting internal LCD.
If not possible, try to get access on the SSD in Target Disk mode.

Caps Lock light reacts correctly, or just stays on?
 

nicerepairs

New member
Disconnected internal LCD, external video not turning on. (It used to, but after a few screen replacements it stopped)
I'll try Target Disk mode.

Caps Lock light reacts correctly.
 

nicerepairs

New member
To clarify even more:

On external monitor it has signal, but screen stays black (slightly lit but still black). Monitor detects that something is plugged in.

Tried Target Disk mode, unfortunately doesn't work.
 

2informaticos

Administrator
Staff member
Then you should get access to its SSD in Target Disk mode.

If can't get external video, then iGPU is damaged; not only eDP output.
 
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