Strange Backlight problem g51

Hi everyone,

New person here, been trying to find a solution to my problem for a while now and haven't found much related help to it.

Anyway, to the point:
I have an ASUS G51vx-RXo5 (the bestbuy model). Recently I cracked my screen on accident and have been having trouble replacing the LCD screen. I installed a new screen, connected everything, booted it up, and the picture showed up but the backlight didnt.

The original screen model: N156B6 L04 C1
The replacement screen model: B156XW02 v6

Here's the kicker, the backlight didnt work when I first turned it on, but after 30 minutes or so, it kicked in and for the next few hours worked flawlessly. But when I restarted the computer, the backlight didnt stay on. It turned off, and hasn't gone back on even when I let it run for 2-3 hours.

One last thing, I tried putting back the cracked screen in and seeing if the backlight problem persisted, and to my surprise, the backlight kicked in instantly on the old cracked screen.

Has anyone had any similar experience with this type of backlight problem?
Any help greatly appreciated!

EDIT: Sorry forgot to add, this is the 3rd screen that I ordered, I thought the first one was defective, returned it, ordered another one, same thing (also had same problem, turned on once and never again) . Now Im on my third on and at my wits end....

 

The CCFL bulbs in the LCD may be going bad. If you rapidly hit the hinge switch or open and close the display, you might be able to get the backlight tubes to start up again.

Since your old display backlight works fine, it's probably not the inverter that is bad.

 

Hey ALLurGroceries, I thought it was the LCD too, but I tried several ones, I returned the original one I got, and the second one too, now im on my third one and still having the same issues, is there anything else that could be causing this?

 

It's possible the pinout is wrong for the LCD, try searching the net for the model numbers and the keyword "datasheet" and you should get some PDFs with the pin assignments. Note that the revision numbers need to match on the datasheet you found for the LCD; different versions can have different pinouts, connectors, and finishes.

edit: found them...
http://www.deaking.cn/uploadfile/B156XW02V6.pdf
http://www.lcd-screen.com.ua/data/pdf/CHI MEI (Chi Mei Optoelectronics Corp.)/N156B6-L04.pdf

The only differences are pins 22, 25, 28 on the N156B6 which have no connection and are ground on the B156XW02. That shouldn't matter...

Nevermind what I said about the CCFLs/inverter, those are both LED screens so there is no inverter and the backlights won't fail easily.

Does the screen ever flicker if you move the lid back and forth or flex the LVDS cable around? Did you try opening and closing the lid repeatedly (that sends the on/off signal to the backlight so it may get it to come on eventually)?

 

Hey, sorry for the slow reply, got into a car accident last week which kinda put the laptop on hold.

Anyway, thank you for all your help. I tried opening and closing it multiple times without any success and moving and tugging the cable didnt produce any noticable effect. I am in the process of completely taking the laptop apart and having a look at the motherboard, is there anything that I should be on the lookout for that might tell me whats wrong with it?

 

There isn't really any reason to take the whole laptop apart, you only need to get at the LVDS header on the board which is right under the left hinge cover.