Is it the logic board or the Display

The backlight in my screen is not working. I have tried replacing the inverter. And I tried resetting the PRAM. I currently have my computer hooked up to my samsung television and it works fine. Does this mean that the logic board is fine and the problem is in the display? Is there other tests I can do to be sure before buying new parts?

Answered! View the answer I have this problem too

Is this a good question?

Score 0
Add a comment

3 Answers

Chosen Solution

The problem is isolated to the display subsystem, but do you see a faint image, or is the screen completely dark? If you see a faint image, you most likely need to replace the inverter cable (which goes bad infinitely more often than the inverter itself). If that doesn't do it, then the screen itself is the issue. You've proven the GPU works by successfully using an external display.

I don't agree with the "backlight is definitely powered from the video processor" statement...the GPU doesn't have a lot to do with the backlight...it's the screen electronics, inverter, and inverter cable that light the screen, and when any of those are bad, you'll often see a faint image with no backlight. In this situation, the GPU is working fine and doing it's job, providing the image, but the backlight is not its problem.

There are cases where a logic board is bad and prevents a backlight from working (even when the screen, inverter, and inverter cable are good), but I don't believe those cases are specifically related to the GPU...I think this situation has more to do with the logic board failing to provide power to the inverter, and, again, I don't believe the GPU has any part of that.

Was this answer helpful?

Score 2

Comments:

there is a faint image simply no backlight. I tried replacing the inverter; assuming that the inverter and associated cables are good, you would advise a replacement screen???

by

First I'd recommend replacing the inverter cable. Like I mentioned, the inverter cable often gets crimped and is FAR more often the problem than the inverter itself, and it's a lot cheaper than a screen obviously, so it's a better place to start. If that doesn't work, then all you can do is replace the screen.

by

Add a comment
Most Helpful Answer

You are correct. The video processor on the logic board is good. Your problem is isolated to the display.

Was this answer helpful?

Score 3

Comments:

A solid answer +

by

So the backlight is definitely powered from the video processor? Should have been my question all along...

by

Add a comment

Hello, I just read this article and I am having the same problem. The problem all started with the screen flicker with the moving of the screen up and down. I tried changing the inverter, the inverter cable (the one with the negative ground loop...combined with the isight cable), changed the display data cable...After I did all this...actuallly now there's no more flicker...the screen just has the faint image...should i also try changing the inverter cable on the other side (pink and white one)?

Was this answer helpful?

Score 0

Comments:

Hi there, you should really ask this as a new question. right now it appears as if you are answering an older question. Check on the right hand side of this page and you will find a link "Ask a Question" it's not hard to do but it makes sure that people see you are asking. Good Luck

by

Add a comment

Add your answer

Grant will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 0

All Time: 1,635