It's retro laptop time - TI TravelMate 4000 WinSX

[rubber_jonnie]

Re: backlight. It's probably the cold cathode florescent tube gone bye-bye rather than anything else.

I did consider that if the machine was running off battery the backlight would be off, but all the info I've found suggests otherwise. The BIOS too suggests this isn't the case either.

I agree, it is likely the CCFT that's gone, it wouldn't be the first one I've had this happen on. Have been wondering if there's a way to replace with LED's.

[rubber_jonnie]

OK, so a little investigation and I can see something. Power is off:

IMG20251016111253.jpg (177.92 KiB) Viewed 966 times

And power is on:

IMG20251016111227.jpg (164.87 KiB) Viewed 966 times

So there is a little bit of light being generated by the tube, but clearly insufficient for the job at hand. Also, if I turn up the brightness that is reflected at the tube, but still not enough.

The inverter has a 10v supply. My assumption is that it's enough, however I'm wary of trying to measure the output of the inverter as we're looking at (As best I can tell) could be up to 600v AC.

My meter does supposedly support up to 600v, but I'm wary nonetheless.

So at present it could be:

1. The inverter can't generate the voltage required to fully illuminate the tube.
2. The tube is tired and won't fully light.
3. A combination of both.

I am leaning towards number 1 at the moment though, but you neve know with the tubes.

[rubber_jonnie]

Looking closer at the tube, I see it's quite dark at the top end:

IMG20251016125434.jpg (170.94 KiB) Viewed 960 times

So thinking it does look like the tube.

[rubber_jonnie]

So, I also need to get back to this machine, it could be a useful tool, so I need to figure out what I can do about revitalising the display.

Onwards and upwards

[rubber_jonnie]

So, CCFL tubes are available, mine is 7.5"/190mm and 4mm diameter so I'll see what I can get hold of.

There is a UK company (Backlightweb) so it might be relatively simple.

They also make LED replacement kits so I'll have a look but a new tube would be simplest.

[rubber_jonnie]

And I have a tube on order

The price? £7.35 + shipping of £4.99

[HigashiJun]

Nice find !

[rubber_jonnie]

Nice find !

I was a bit shocked to be honest, but the website I linked to above is quite a find and covers a lot of different CCFL options.

I managed to get a bare lamp and will have to solder the wires on myself but it does mean I know the wires will be the right length.

We'll see when it arrives

[rubber_jonnie]

OK, backlight has shipped, lets see how it does when it arrives!

[rubber_jonnie]

OK, so the backlight has arrived and whilst I seem to have mucked up the measurements slightly (It's a bit longer (5mm) and narrower (4mm vs 5mm) than the original) I believe that it should still fit ok and as long as it isn't the inverter that's dead (I don't think so as I had a bit of a zap off it, then the new one should do fine.

If not then they are relatively inexpensive so I could order another. We'll see, I just need to transfer the wiring over first.

I'll report back later.