Question laptop screen started by flickering then dim then black

[AnwarElhamaky]

i have toshiba satellite l750 PSK2YV
the screen at first started to flicker but not always then the problem became frequent when i opened it and press the screen cable the screen return to its normal situation after many times the screen become so much dim but when i tested the screen on other laptop it works fine then the screen become black when i assembled it to the laptop 😭😭 but all of those does not happen on external monitor using HDMI the laptop work fine
please help i want to know where is the problem, is it from cable or graphic card or motherboard ??

 

[jsmithepa]

The backlit LED is dying?

 

[AnwarElhamaky]

yes but when trying this screen on another laptop it works fine !!!! but doesn't work in mine

 

[jsmithepa]

is the backlit part of the panel or something separate? when it flickers off do u still see the image on-screen with a flashlight?

LED backlit shines through LCD display panel, so which is faulty?

 

[AnwarElhamaky]

it is a part of the panel

 

[Prostar Computer]

Sounds like a bad video cable. If you can find the part number for it, they're usually pretty cheap, but replacing it might be a little difficult.

 

[AnwarElhamaky]

ok but some people told me that my graphic card is broken is that true ??

 

[Prostar Computer]

If the laptop works fine on an external monitor, I doubt the graphics chip is the problem.