screen went dark on my T30

[pengang]

The LCD display on my trusty old T30 (since July 2002) went dark this morning. When I was checking email in the morning, the screen was still bright but flickering. I went away, and when I returned about 2 hours later, the screen went dark.

I am now using the external VGA port to write this message. I would like advice from fellow forum members on the best approach to fix this problem. Thanks in advance.

[rkawakami]

The cause of the loss of the backlight can be due the these things:

- failure of the inverter board
- failure of the backlight (CCFL) inside the LCD panel
- motherboard issue

This can be confirmed by:

- with the system booted WITHOUT an external monitor connected, shine a bright light on the LCD. If you can see an image, then at least the video signals are being generated correctly.

No cost things to check out first:

- with the system off, flick the lid closure switch several times (it could be dirty)
- remove and re-seat the inverter board and all cables to/from it
- remove and re-seat the ribbon cable at the motherboard connector

If that doesn't help, then the cheapest (and easiest) part to try to replace is the inverter. Usually available off of eBay for less than $20. If that doesn't work, then it's probably time to think about the cost of an LCD panel. Replacing the CCFL is possible but it is a delicate job. Lamps can be had for about $10-$20.

[pengang]

Ray, thanks for your helpful advice. I spent the morning opening up my T30 to make sure the connectors are sitting tight. Didn't make a difference. LCD is still dark although I can see that there is an image similar to the image on an external display through the VGA.

Will proceed to get a replacement inverter card and cross my fingers....

[tfflivemb2]

It looks like I am going to be going through the exact same thing tomorrow, with a T30 that I just bought off of eBay. I am hoping that it is the LCD switch. If not, hopefully only the inverter, since the LCD was super bright and clean.

Ray, do you think that it can be the inverter if all of a sudden the screen goes black DURING a program, versus during the boot process?

[tfflivemb2]

UPDATE: I finally got to check the T30 a little more thoroughly, and it turns out that the LCD had been removed in the past, and the wireless antenna was run between the LCD cables and underneath the inverter, instead of above the inverter. It caused the connection for the backlight to be intermittent, when there was pressure added to the upper half of the Thinkpad.

So, this might be something for the OP to check.

[rkawakami]

Don't know how I missed your previous question about the inverter going out during use vs. at boot time...

The flickering mentioned by the OP could be the inverter, the CCFL or some other component about ready to give up. I would say that it's possible that one of the fuses (thermal and regular) I've found on the T23 motherboard is protecting the inverter. There could be a similar one in the T30.

Saying that... when I tried unsucessfully measuring the output voltage from the inverter with a standard digital multimeter, I got a quick emission of photons (i.e., a spark), vaporus plastic, a melted clip (the source of the grayish smoke) and a couple of white hairs. The inverter still worked in another panel and the motherboard still worked with another lid assembly. So if there was/is a fuse, I didn't trigger it with that silly experiment.

[pengang]

Well, the inverter arrived and I plugged it into my T30. Didn't make a difference. Now, I'm looking to replace the LCD panel - I hope it is not an issue with the motherboard.

[rkawakami]

Before you go out and spend the "big bucks" for a panel, be sure to double-check:

- inspect the video ribbon cable for any chips, cracks, tears or bends, especially where it comes up from the base into the lid and where it bends to connect to the inverter board.
- with NO external monitor connected, boot the system. Do you still see a faint image on the LCD?
- with the laptop already running, connect an external monitor and use the Fn+F7 key combination a couple of times to select between only the external monitor active (first push of Fn+F7), then both active (2nd push), then back to only the LCD active (third push). If that doesn't activate the backlight and you still are seeing the video image on the LCD when it should be active, then I'd say it's probably the CCFL which has gone out (could still be a motherboard issue).

The ribbon cables are generally $20-$30 on eBay (two different styles depending upon XGA or SXGA+ panels). I have not priced out the panels but they are probably around $120 (XGA) to $200 (SXGA+). You could always try getting a complete, known working, lid assembly. I've found that at least with the T23 installed in a port replicator, you can remove the keyboard, unplug and lean back the original lid, plug in the replacement lid, then turn the system on with the power button on the port replicator. A very quick and dirty way of determining if the panel is working or not. If the seller has a generous return policy and the new panel doesn't work, then you are only out the shipping costs and you can go on to researching a motherboard swap.

[pengang]

Ray,

Yes, I see the faint display on the LCD panel. In fact, I am using the T30 right now in composing this reply via an external monitor as display. As I scroll the screen, the LCD panel has a faint scoll as well.
I doubt that it is the LCD cabling.

Regards,
Peng

P.S. I noticed you are based in Silicon valley. I am too...

[pengang]

I bought a T30 SXGA panel from eBay last weekend. I received it this morning. Hooked it up to my trusty olf T30 (since July 2002), and it works! Now, I have a higher resolution screen.

Thanks to all the advice rendered.