R50p no backlight - which part is faulty?

[dsandlund]

I'm looking for help on determining which part(s) is/are faulty here, I have replaced basically everything and it still isn't working properly. Any input would be greatly appreciated!

My R50p would crash each time I moved it, lifting it by the palm rest caused the video to go blank. After looking around the internet, I determined that this was due to a loose graphics chip.

Recently I got a used motherboard for the laptop off the bay, and everything seemed to be working perfectly again. I installed the operating system, and when I get back from dinner a couple of hours later, the backlight is dead. No amount of fiddling around would make the backlight come back to life. The laptop seemed to be working nicely otherwise, judging from the faint dark image on the screen, but no backlight.

I figured that the inverter must have died so I ordered a new one from IBM. Upon installing the new inverter however, the screen would remain dark as before - no backlight.

Although I had not noticed any of the pinkish casts that I have read about, things that would indicate a broken backlight, I figured that I had now replaced all parts of the laptop except for the screen. So it could only be the screen, right? So I bought a used screen off the bay.

Guess what, the new screen didn't help. The computer itself seems to be working, but the screen will only display a very dark and barely visible image (ie, no backlight).

Is there some way of telling which part is broken? Are both my screens broken? Are both my inverters broken - including the new one from IBM? Could it have something to do with the motherboard? Something else?

There does not appear to be a loose connection somewhere - I've tried reconnecting everything several times, as well as carefully fiddling around with the parts while the computer is running.

Is there something more I could try?

Naturally, at this point I'm very much regretting spending the money on all the parts, instead of just buying a new laptop from the start!

Any ideas would be greatly appreciated!

[RealBlackStuff]

If you look at the back of the LCD itself, you will see a metal strip along the bottom.
Behind there sits the backlight or CCFL tube. That has the length of the screen and is only about 2-3 mm in diameter.
That's the sinner that needs replacement.
Se this webpage for more info and instructions (you have to dig around!)
http://www.lcdparts.net/CCFL.aspx

[ajkula66]

I've owned a X31 that had behaved exactly the same as your R50p, and I've gone through all the steps that you have...

New motherboard was the only solution...

My assumption is that the replacement planar that you got was defective to begin with...

Good luck.