Problem with inverter, LCD backlight or LCD cable?

[Troels]

Hello,
For some time i have used a T42p UXGA Flexview screen in my T42 without any problems which worked great. That UXGA screen has some problems with pressure marks, so i wanted to re-install the 15" SXGA+ Flexview screen that it originally came with.

The 15" SXGA+ screen worked great before i removed it. I stored it ontop of a bookcase, and has remained there for 6 months - completely untouched, complete with the LCD cable and ThinkLight atached.

I installed the SXGA+ screen again yesterday and reassembled everything as it should be but:

- There's no backlight.

I pulled the screen lid plastic frame and pushed on the inverter.
It booted into windows XP at 640x480 resolution.

- This made the backlight work sometimes as i pushed.

I changed the resolution in display properties to 1400x1050, and the resolution changed correctly.

- Suddenly i smelled some smoke, and i noticed it came from where the LCD connector connects to the motherboard.

I quickly shut it down and removed the battery.

I thought it was the inverter, because it must have drawn a lot of current from the LCD connector, so i ordered a new one from IBM, which arrived today.
I assembled everything again, and still no backlight, but there is an image on the screen as there ought to be. I do not want to press the new inverter, but assume the result is the same.

Upon removing the LCD cable from the motherboard, there were NO burnmarks to see whatsoever.

-----

So any suggestions on what is wrong?
Has anyone tried something similar?

[richk]

When you first changed the screen, what did you change? (panel, assembly, cable) SXGA+ and UXGA use the same inverter and different cables. Did you get the right inverter? Part number? My first guess is the cable (switch near connector).

[Troels]

I ordered a 93P4161 inverter, but recieved a 39T0361 which is the same, except it is RoHS compliant, which they must be here.

Actually i inspecpted the cable again, and you're right, it's ruined. Four copper wires have been torn over in the par that goes to the inverter.

I swapped out the SXGA+ cable with the UXGA cable because they had the exact same model no.s etched onto the cables near the connector.
Now it works, but obviously it now thinks it is UXGA, and thus a part of the image is just cut off. Changing to 1400x1050 just makes it interpolate the image and still stretch to 1600x1200.

At least now i know i need a new SXGA+ cable. Thanks

[pianowizard]

That UXGA screen has some problems with pressure marks,

Does this option appeal to you?

[Troels]

Unfortunately i must say no. I swapped the screen out because i sold the T42 to my mother, and even then SXGA+ is nearly too high, but better for her than UXGA, since many of the applications refuse to scale fonts.

It is a really great deal, though!

But i have been thinking of making a desktop monitor of a UXGA 15" panel, so i will have to keep yours in mind, but i don't know how much the rest of the electronics are going to cost yet.