2015 Macbook Retina Screen flashes

[Ray818]

I have a 2015 Macbook Pro retina 15-inch 820-00138 A . When I got it the screen rapidly flashes and after a minute screen goes completely blank. If I disconnect the LCD screen and connect Monitor output I get good video with NO blinking. I have already replaced with L8300 purchased from your store and it seems like the problem is somewhat fixed but now it will blink and the entire computer would turn off like its going into some deep sleep and then suddenly come back on. When I test that component that I replaced when this happens there is no voltage anywhere so definitely this board is going to sleep now. What do you recommend I replace now. I was thinking the [h=1]SL6259[/h]

 

[JohnB8812]

Did you even try a known good screen?

 

[Ray818]

yeah i connected a cracked good screen and the same thing happens. The backlight and video go out.

 

[dukefawks]

What is SMC_LID doing? Is this also flickering when just sitting on the boot selection menu and not is OSX?

 

[Ray818]

I have it booted into OS
When I connect the screen and external display the external display works fine but the LCD flashes rapidly and then dies. I check the chip i replaced and its getting 5V when flashing but when it dies no voltage.

 

[dukefawks]

Any history? Check if any of the resistors around the LCD connector got chipped off. When the LCD totally dies is the external still fine?

 

[Ray818]

yeah exterior is still fine. Ive checked everything I can see and it looks fine.

 

[dukefawks]

Any history? Did this just happen or was is liquid/dropped/messed with? Does it always happen or can it be ok for a while? Can you force it to happen to flex or tap on the board in certain areas?

 

[Ray818]

no liquid damage. I looked at the board and it seems like it was an apple warranty job because the LCD connector looks like it had been replaced. I saw evidence of flux on the connectors. I'm thinking maybe the screen is bad but I connected another screen and it does the same thing with another screen. I have to maybe trace the LCD circuit back and check each component. I really dont know how to test short to ground. I kind of understand it but Im still learning how to test components to see if they are short to ground.

 

[dukefawks]

An Apple replacement board will have a small white sticker on the bottom with the part number on it. If the LCD connector was messed with that either means the board had this issue before or the connector was damaged and is not soldered correctly or damaged again.
At this point replacing the connector just to be sure seems like the first thing to do.

 

[Ray818]

OK ill order one from you guys and replace it. Thanks. WIll keep you posted.