Laptop has lines on screen - replacement is the same

I'm replacing the screen on a friend's Toshiba Satellite A505, because the old screen was white/gray with lots of lines running down it.

The replacement screen is the same way.

It works fine when output to an external display(everything looks fine, no lines or discoloration).

My first thought was the GPU is bad, but since it works with an external monitor, I'm not sure anymore.

Sent from my Nexus 4 using Tapatalk 2

 

LVDS cable maybe.

 

I forgot to mention the new screen came with a display cable.

Sent from my Nexus 4 using Tapatalk 2

 

The GPU is the Intel GMA HD graphics from what I see, so since it works on an external, I don't think that's [directly] the problem. More likely it's related to the board though and not the screen or cable.

 

That's probably it. The household this laptop resides in is pretty hard on their computers.

 

Do bear in mind that the outputs from the GPU are separate for LCD (digital) and VGA (analog) and that one can work fine while the other channel is damaged/shot.

Sounds to me like that Toshiba needs a new board.

May I be wrong on this one.

Good luck.

 

You usually see this kind of error with faulty vRAM on graphics card. It is the signature symptom. My thought is maybe the LVDS port is damaged in some way in which case a replacement motherboard is required.