P-7811 FX new LCD screens, have backlight but nothing shows up

So I ordered a new LCD screen for my P-7811 FX with the 1920x1200 resolution due to ghosting effect and double lines on the screen. I can confirm the old one works--image shows up with the said effects. HDMI to TV displays just fine. The new one came and it does this:

Backlight is on. When something new pops up on the screen, it shows up, then fades into black oblivion.


So I got an exchange, and the new one does this:

Backlight is on, but no image.


Any ideas, based on these behaviors? Or is it something on my side?

 

It appears you have two bad panels. That is assuming these are supposed to be 100% compatible.

 

The seller is saying they tested both LCDs--one that I shipped back for exchange and the second one before they shipped out--and they said both work fine. They suggested it could be something on my end. If the backlight works, what else could be wrong on my end?

 

Can you get any picture on a external monitor or TV? I would sure try that. If no picture on external monitor then I would suspect that the GPU has gone bad.

My bad, reading first post again it looks like external monitor/TV works so GPU should be OK.

 

I am assuming, other than ghosting, the original panel still works fine. If so then there is an issue either with compatibility or the cable/connections. That is if the picture is being lost, if it is just the back lights then it could easily be something else.

Now the cables could be fine but since a different panel it may not be compliant. I noticed two things first it there seems to be a lot of banding when no picture is present. This is usually either a bad cable or incorrect pin outs. Secondly on one the videos it looked like only 1/2 of the picture got well lit. I think ours is a single CFL and there were some screens that looked compatible but they were dual CFL.

You have to be careful as if memory serves there were 3 screens that looked like they would work back inn the day but only one of them truly did.

 

The part I didn't hear was did the OP make sure his LCD corresponded to the replacement P/N? If they didn't do this or get a service manual from gateway for the exact part number finding the right screen will be next to impossible. It may says 78 screen but does that P/N match if then obviously that isn't the right P/N.