Very dim display on Compaq Laptop

[Arcadio]

A client brought a laptop for repair. The screen is extremely dim, you can't really see anything unless you look very close. I thought it might be the inverter or the actual LCD screen. I replaced the inverter, but that didn't fix the problem. I replaced the LCD screen, and this didn't solve the problem either. I wonder if the problem is the video card, but if it was, I wouldn't expect to see anything on the screen. The computer boots fine, and it works with an external display.

One thing I should mention is that in the event viewer on Vista, it mentions some "Video problems".

What could it be?

 

[14049752]

Sleep switch. adsfasdgasdf

 

[Cbrooks]

I'd try booting into something like UBCD4win and making sure its not software related.

 

[NeutronTech]

Did you replace the backlight too?

 

[Arcadio]

It's not software related. The compaq logo at boot-time is very dim as well.

 

[Martyn]

Did you replace the backlight too?

It would be in the screen he replaced.

 

[iisjman07]

are you sure the replaced inverter works?

 

[Arcadio]

are you sure the replaced inverter works?

Well, I bought it new, but I can't say for sure.

 

[Martyn]

I've just had a similar problem and replaced the lcd cable, all ok now. The old cable looked fine and in the absence of a pin out diagram I got a 2nd hand one on Ebay.

 

[TLE]

Well, I bought it new, but I can't say for sure.

Martyn posted a link a few days ago on how to test an inverter.

http://www.laptoprepair101.com/laptop/2009/05/04/how-test-lcd-screen-inverter-in-laptop/