2009 iMac Screen problem, please help!

[lightningsalesuk]

I am running a 27 Inch 2009 i7 iMac which was having problems, The graphics card has been repaired before.

When I turned it on It had these lines on the screen.

I was told it was an LCD problem by a user.
I went ahead and ordered an LCD, I installed it and booted it up again and as you guessed the problem is still here.
Is this a graphics card fault or and LCD fault? (Second LCD)

I bought a cable to attach it to an external monitor and there is no problem on the external monitor.

 

[redheeler]

As this is a common problem given the age of these Macs (my Mid 2010 27" iMac shows it as well), it's possible a used replacement LCD would also have it.

 

[lightningsalesuk]

As this is a common problem given the age of these Macs (my Mid 2010 27" iMac shows it as well), it's possible a used replacement LCD would also have it.

The LCD seller confirmed that the lines were not on the model when tested and showed me pictures of it on the testbench.