Screen goes black.

[newyorkpaulie]

Lately I have a problem with my screen going black. If I tap the key combo Fn/F7 (display toggle) a few times it comes on again, but after a while it goes black again. It never self-fixes, but the F-Key tapping always works, but just for a short while. Thinking it might be the keyboard I swapped it out with another one I have, but no luck. Any ideas anyone? Thanks!
BTW, this is a T30 running Linux (same thing happens when I run WinXP).
[Added Later] - I had made a change in memory and just found some references that memory density could have an effect so I will play with that.

[ichhabegedroppen]

Try using an external monitor and the Thinkpad screen at the same time, if internal screen goes black, but external screen still works, its probably a backlight inverter. Try using a flashlight to light up the screen and carefully look for a faint image still on the screen when it goes black.

report back with your findings, it's common for backlight inverters to go wrong and they often only work half the time or less.

[newyorkpaulie]

Try using an external monitor and the Thinkpad screen at the same time, if internal screen goes black, but external screen still works, its probably a backlight inverter. Try using a flashlight to light up the screen and carefully look for a faint image still on the screen when it goes black.

report back with your findings, it's common for backlight inverters to go wrong and they often only work half the time or less.

Thanks for the suggestion. Trouble is, I don't have an external monitor. If in fact it is the backlight inverter - what's the fix? Is this something I might try? I've gotten under the hood to do other things, like swapping out the CPU, exhaust fan, keyboard, etc..

[RealBlackStuff]

The inverter sits under the LCD bezel. That's all you need to remove to get at it.
About $10-15 on eBay.
Make sure to remove battery and AC before you start.

[newyorkpaulie]

The inverter sits under the LCD bezel. That's all you need to remove to get at it.
About $10-15 on eBay.
Make sure to remove battery and AC before you start.

Sounds very doable on my part, but I don't think that's it 'cause when the screen went black again a strong flashlight shining on it didn't reveal anything. Tapping Fn/F7 a few times brings back the video. What does that point to do you think?
BTW, this is a T30 I got for a relative so I feel obligated to get it working. Barring that I will have to replace it. Luckily I have my own which is working fine - allowing me to get on this forum for instance. Thanks for your help!!!

[Just Added] - Bingo! - It may be the backlight after all! When I shine the flashlight obliquely I CAN see a screen image and when I change the screen the image changes too. So do you think my next step is to swap out the inverter?

[RealBlackStuff]

The new inverter might do the trick.
But first check the LCD On/Off lid-switch, it may be loose?
Otherwise replace the CCFL or get another working LCD.

[newyorkpaulie]

The new inverter might do the trick.
But first check the LCD On/Off lid-switch, it may be loose?
Otherwise replace the CCFL or get another working LCD.

When I give the lid-switch a tap the screen wakes up.
Would this still indicate a faulty inverter do you think?
.

[RealBlackStuff]

"Hammer" that switch a few times.
It may be a little loose or corroded.
The fix would be another LCD cable if this is the cause.
Or remove that switch altogether and solder a permanent wire across the old contacts.
The LCD would then always be ON, even if you'd close the lid while running the T30.

[newyorkpaulie]

"Hammer" that switch a few times.
It may be a little loose or corroded.
The fix would be another LCD cable if this is the cause.
Or remove that switch altogether and solder a permanent wire across the old contacts.
The LCD would then always be ON, even if you'd close the lid while running the T30.

Hammering didn't stop the winking out.
Is the switch a part of the LCD cable?
I was going to try this as a test (of the switch) if it's a single circuit on/off type:
Solder a wire to each terminal and put the case back together.
See if connecting the wires eliminates the blacking out.
Think this is a good way to test it? If it works then I could permanently connect the terminals and live without the lid-closing action. I don't really need it anyway.