T23 with dead backlight - changing external screen res?

[HDRW]

My T23, with 1400x1050 screen, has had its backlight fail (it was showing pink for a couple of minutes after power-on, for some months, then yesterday it started flickering, and then went completely black).

I'm going to get a replacement CCFL tube (292x2mm I believe) but in the meantime I'd like to use it with an external monitor.

Problem is, the monitor I have will only handle 1280xWhatever resolution so won't display anything past the initial booting (displays a box telling me to change the resolution). But without seeing the screen it's not possible to change it!

Is there a way to change the external screen resolution "in hardware" (ie before the operating system loads) so I can use the thing?

Cheers,
Howard

[RealBlackStuff]

Boot up in Safe Mode and set the screen resolution back to e.g. 1024x768 or 800x600.
That should get the external one going, and you can then pick a suitable resolution for it.
Reset it again when you have tackled the CCFL and are ready to put the LCD back in.

[HDRW]

RBS,

OK, I'm not actually running Windows, but you reminded me that eComStation (a descendant of OS/2) also has a sort-of Safe Mode which interrupts the boot sequence and allows changes to be made - it's been so long since I've needed it that I'd forgotten it was there!

I'm now running happily on the monitor - Thanks!

Now when the replacement CCFL tube arrives I just need to get my courage up to dissect the display to replace it...

Cheers, Howard

[HDRW]

Well it looks like it may be a case of "The operation was a success, but the patient died"

I got a replacement CCFL tube (actually two, just in case!) and it's much harder to change than I thought - the main dismantling of the Thinkpad is OK (it's all in the manual), but once you get the LCD unit out of the lid you're on your own. The only web site I found that shows the job (and as it happens it was exactly the same type of screen as mine) seems to skip over the tricky bit - it doesn't actually tell you how to get the unit apart to get to the tube, or how to reassemble it!

I found that both ends of the tube showed signs of overheating - the plastic covering sheet was charred, and at one end the glass tube itself was broken at the overheated part. The other end broke off as soon as I touched the wire.

I worked out that you have to remove the sticky tape, one reinforced ribbon cable, one small ribbon cable underneath, and three screws, to be able to lift the flexible PCBs, you can then bend open the catches holding the LCD stack into the metal frame. The only way to get the CCFL tube out was to "open" the plastic rear frame (hinges to one side on tape) followed by opening the rear white plastic sheet that is presumably the rear refective surface, and whic wraps around the CCFL. Taking out the broken tube was then trivial, and unsoldering and resoldering the wires was fiddly but doable with care.

Getting the new tube into position and dressing the long wire into place was fiddly, and the stack of sheets slid around in relation to each other. Eventually I get them all lined up enough to get them back into the frame and clip it shut.

After reassembling eveything I powered on, and there was a bright area across the bottom of the screen (perhaps I didn't get the tube in quite the right place?) and the rest of the screen was a dark blue, but not evenly - there was a rough border that was different. The screen display then showed a series of lines down it, lighter and darker blue, but very muddy and indistinct. And that's it - that's all it ever shows. The machine boots OK and works fine on an external monitor, but the LCD is not working.

So: Have I wrecked it or is it possible I did something that's fixable? Is the alignment of the sheets in the LCD stack critical, and if so how do you get it right?

Any advice where I can go from here?

Cheers,
Howard

[RealBlackStuff]

Yup, you've wrecked it, and it will never work properly again .
Once you take layers apart, it's a goner!
Was that a Samsung or a Hitachi LCD?
Samsungs are relatively easy compared to Hitachis, which are a real pig to work on.
I've done several Samsungs and only one Hitachi ever.
I sorta madea it worka, but it was a botched job, and I've sworn to never work on a Hitachi again.
It's definitely easier (and cheaper if you consider hourly rates) to just replace a (Hitachi) LCD.
I described how to swap a CCFL here: http://forum.thinkpads.com/viewtopic.php?f=31&t=88991

[HDRW]

Dammit! So are you saying that a worn-out (£5) CCFL means replacing the whole LCD? (£££!)

It's a Hitachi, and I was taking my cue from this site: http://kihwal.fayoly.net/proj/t23_bl.html where he replaces the CCFL on exactly the screen I have (same part number) and if you look towards the end there's a photo that shows the layers separated. I didn't do that, but they slid about in relation to each other (the furthest was less then half an inch). They slid really easily under their own weight when not far off horizontal. I tried to get them lined up again, assuming that getting them back into the frame meant I'd got it right.

So howcome he succeeded and I failed? What could I have done to prevent the disaster?

I suppose my choices are to use it only in non-laptop mode (with a monitor) henceforth, or try to find a replacement LCD - any other ideas? This model of T23 (14.1" 1400x1050) is as rare as hen's teeth, so the chances of finding a replacement LCD seem remote.

It's something of a tragedy, because this is my favourite laptop, and is my daily-use, carry-around machine.



- Howard

[RealBlackStuff]

That person was lucky to get it working again, but he didn't tell you about the hair(s) and dust specs he's now got inside his LCD!
You NEVER so much as touch the column and row drivers if you can, let alone remove them!
Check out some tips from the professionals:
http://www.lcdparts.net/howto/default.aspx

Please note that they (supposedly) work in a clean-environment room.
I don't quite agree with their methods (compared to my own description), but I guess their instructions only apply to some specific types of LCDs.