LCD backlight stays off occasionally-BACKLIGHT or INVERTER?

[underclocker]

I have a fine T41 whose backlight occasionally won't turn on, maybe one in ten times. You can definitely see the dark images on the LCD.

To get it turn on, I just have to suspend, shutdown or hibernate, then turn it on again.

Once it's on, it will stay on until another rare time that I try to turn it on from suspend or off/hibernate.

When the backlight is on, the image is great, like any other T4x - bright, no pink or other hues.

Could it be the inverter? What does the inverter actually do? (Could it be the cable?)

Thanks for the help.

[ajkula66]

I'm going to say "no" to the cable, and "maybe" for the backlight...

Add another "maybe" for the motherboard....

[rkawakami]

Answering in reverse chronological order...

Possibly. The inverter converts a DC voltage to an AC voltage that fires up the CCFL (backlight). Yes.

Could also be a dirty lid switch, a weak backlight or motherboard issue. Here's something that I just found:

http://www.fonerbooks.com/test.htm

Uses a cheap digital multimeter to measure the frequency of the inverter's oscillator. More of a high-tech solution than my neon bulb high voltage detector...

[underclocker]

There were no issues with another LCD assembly, so I'm going to assume the mobo is fine.

Although I don't feel the labor is worth the removal of the LCD bezel (10 screws and 10 screw covers), I did it again since I had a couple of known good inverters on hand (don't we all?!)

So far, so good. But I'll report back after some more days and tests pass. Like I said, it was intermittent.

Since the LCD image and brightness are really nice, I'm hoping it was just the inverter and not the backlight.