820-00840 - Lines on screen

[Alanley]

Hi

Had an A1708 EMC3164 in for repair.
Lines on screen. (See Image)
Image is perfect on external screen
Boots OK, works OK, although I've pulled the drive in the image
All voltages are within limits.
Tried a new screen and LCD cable(I know it's never the cable.)
Tried PRAM reset just in case.

Works OK on external screen.
Do you think it's toast?



No Liquid damage - clean.

Alan

 

[2informaticos]

First of all, welcome to the forum!

Did you try full LCD assembly?
Check if the machine is covered by Apple program to change the LCD.
There is no dedicated GPU, only iGPU, which uses internal RAM.
So cannot be RAM issue and low chance to be just CPU eDP output damaged.

 

[Alanley]

Thank you for the welcome, It's nice to be here.

Yes, the LCD in the image is the replacment screen, Full assembly.
I'll post the image of the original and the External display later.
The machine doesn't look as if it's covered by the Apple program, as it specifically mentions the Backlight issue, unless you can advise me different.

 

[Alanley]

Ok,
Back to this problem.
Didn't get a chance to upload photos yesterday.
This image is of the original screen

This one is of the original screen, when we first get backlight voltage, before we get the Folder icon.

This is the replacement screen, Full Assembly.


I've also disconnected the backlight and injected voltage from my Power Supply, and there it's exactly the same.
Image on an external screen is perfect when it's booted.
I have spoken to Apple and sent them an image, and they state that it's not covered by the Apple Program.
I can't see any spikes or modulation on any of the power supplies.
I've checked all the lines into the LCD on J8500 and they all look OK, but it's difficult to know what's right or wrong on these pulses.
When it boots up, apart from the lines, it works perfectly.

Does anyone have any more thoughts apart from a Hammer.

 

[2informaticos]

Try known good compatible LCD assembly...

 

[Alanley]

This was a new one.
I'll order another.
It does look like it doesn't it.
Thanks
I'll report back

 

[daniel_andrei1996]

I had a customer come in with the exact same issue! Even down to the placement of the green/black line. The customer said they'll try to get apple warranty repair but I always assumed it was just a display issue. Crazy to think it might be a board problem