T42 LCD woes

[Werelds]

Hi there

So my T42's been broken for quite a long time now, and I decided to revive it because it's just that awesome. I haven't been able to determine what exactly is wrong with it though, so I'll just get straight to the point: the LCD is very dark, but not entirely black; I can see the Thinkpad/Intel logos VERY faintly when I power it on.

Obviously, the first thing that came to mind was the backlight. Googled around a bit (and ended up here \o/) and replaced the inverter with one directly from an IBM dealer near me (not cheap, but I had good hopes that would fix it). No joy though. Next up would be the backlight itself; ordered a fresh one, but still nothing. The old one was in fact broken though, about a third of it was shattered inside the casing (which was hell to clean up).

Still the same problem; LEDs on the inverter light up fine, it still shows that faint image and when I hook up an external monitor it's all good, so what's wrong here? If it was the GPU, surely it would be a problem with an external monitor as well right?

The model is 2373-A23, the specs in short: Pentium M 1.7 GHz, 768 MB, R9600

Feels like such a waste to throw a machine like this out, because it's still a mighty fine laptop, mostly due to the bloody amazing matte (!) IPS screen :/

[RealBlackStuff]

Welcome to the forum.
The graphics processor (GPU) on your laptop consists of 2 parts, a digital part that feeds the internal LCD, and an analog part, that feeds the external VGA-port.
If one is broken (usually the digital/inside one), the external may still work OK.
Your problem is a loose GPU, plenty of posts about this.
Read the 'Sticky' threads at the top of this T4x forum.
Since you are in Holland, check out http://www.reflowrepairs.co.uk

[Werelds]

Ah so it's separate DACs, so reflowing should do the trick?

I'll have a look around then, see how hard it is in this machine or I might send my board to the UK, at any rate thanks for your response

[poshgeordie]

It could also be a blown fuse - interestingly enough one of the refurbished Board Room boards I've just returned to RBS had this exact symptom and was a fuse!

Go to my signature and download the How To's doc, and from there download the T4x fuses doc. If it's a blown fuse it'll be one of the three around the LCD connector - F3, F7, F8.

I run Reflow Repairs in UK and do please do contact me, either by PM or to nick@reflowrepairs.com, if I can help you.
I'll send you instructions on how to strip down the Thinkpad so the motherboard's still in the base. We'll be able to quickly diagnose the exact problem and repair the board, whether it's an unsoldered graphics chip or a replacement fuse.

[Werelds]

Thanks for your suggestion, I'll check the fuses first thing tomorrow (can't be bothered to open it up again right now). Stripping it down shouldn't be a problem, done it with PowerBooks and MacBooks (not mine, thank God), should be able to do it with this as well. At least the display was much easier to take apart, and more importantly, put back together.

Sadly, sending it over to you guys is a pretty pricy solution for me, equals out to at least €80 (70 quid; assuming NL falls within that 25 quid segment for return shipping) - granted, that's cheaper than what a service center would charge me, but still pricy for an almost 6 year old beast. Something I have to think about.

[poshgeordie]

Price-wise if it's a fuse we would only charge you £20 + £22.50 for return carriage for a stripped down board.

If a reball is needed (that is to remove the graphics chip, replace the old solder balls under the chip with a new set, and to then reflow [solder] the refurbished chip back onto the motherboard), it will definitely extend the life of your laptop.

Having seen most laptops from this era, there is no doubt the T40 range is by far the best made and most robust laptops around and this is why so many of us continue to use them rather than to change to a newer one.