a1278 820-3115 flickering screen

[Jeffotskie26]

hello got this model got flickering screen no oftenly but when
start to use the trackpad it will flicker more.
i tried use the original lcd to another macbook it is fine.
tried also use another known working ram still the same.

 

[2informaticos]

Any history available?
Try changing U9701.

 

[Jeffotskie26]

tried changed u9701 still same.
anyway not the backlight is flickering.
the display is flickering after it boots and when moving the cursor.

 

[2informaticos]

The sound is good?
Run corresponding EFI ASD.

 

[Jeffotskie26]

got startup sound before entering password just notice
in safe mode. after entering password safemode gone.
tried play some videos on youtube there is no sound cant press the volume button.

 

[2informaticos]

Missing sound could explain the problem.
The system tries to "beep" an error; not possible , then image flickers.

 

[Jeffotskie26]

there is no beep error,
just when im playing videos on youtube there is no sound i cant adjust also the volume.

 

[2informaticos]

So you have sound, only missing it on Youtube?

 

[Jeffotskie26]

totally no sound system didnt recognize the sound card.

 

[2informaticos]

Need to solve the sound problem.
Screen flickers may stop after that.

Check the power rails of audio codec.