t43 stopped working after screen change

[thinkmMm]

Since my A31 is not sufficently stable anymore and it lacks Bluetooth to utilise my absolutely fantastic Logitech keyboard I thought I'll get my t43 running...

To make the T43 usable I needed to swap screens with something else (T42), otherwise T43 was working perfectly.
I swapped the original LCD marked LTN141P4-L02 for LTN141XA-L01, of course both 14".
When I turned the laptop on it only worked for about a second or two (fan working, lights on). It shut itself off for some reason and DOESN'T WANT TO START AGAIN.
It's dead, not a slightest sign of life, and no other screens or PSUs make any difference - no lights, no fan, nothing... the damage seems to be permanent.

And so I ask:
WTF happened?!

[RealBlackStuff]

The LTN141P4-L02 is an SXGA+ screen, the LTN141XA-L01 is an XGA screen.
You also need to swap the matching LCD cable, the inverter is the same for both types.

[thinkmMm]

Well, I do understand that there are differences.
And I did not swap the wide LCD ribbon because the plug was exactly the same and I didn't think much of it. I tried this approach many times on different machines and it never rendered the machine useless as is the case now.

My revised question is:
Is it the screen swap that caused a major hardware failure or should I start looking somewhere else?

[RealBlackStuff]

I don't know the problem(s) of your machine(s). I DO know that LCD and cable need to match up.
Unless you create a properly working environment, there is no point in developing what-if theories.
Swapping one part out without the (matching) other should not create the problem you describe.
What is very likely the case: your T43 has Windows with gfx drivers set up for SXGA+ (1400x1050).
When you then throw in an XGA (1024x768) screen, Windows cannot do it's display-stuff.
Disconnect the LCD or LCD-cable under the keyboard/palmrest, hook up an external monitor, and boot up to change the resolution down to 1024x768.
Then match LCD/cable for XGA, and hook it back up again into the T43.
Boot up in Windows, what do you get now?

[thinkmMm]

I couldn't access forum for a while for some reason, that's why I'm replying late.

The T43 starts again. This is as far as good news go...

It only starts (and displays) with the monitor plugged in to its VGA out, the LCD stays blank. But it will only work for a couple of seconds if forced to show anything on LCD (when no other display present). Once it shuts off due to LCD problem it won't start again until I do some battery and PSU on/off manipulations. Seems random, but it's probably just me that can't work out a pattern to make it power up again.
So basically it stops working at all whenever an internal LCD is to be used. I tried this with it's original screen back (after I changed a ccfl in it, because that was why I wanted to replace the whole panel in the first place) and it makes no difference.
I'm far from having any OS installed on it, so everything I describe happens during POST or bios access.

Maybe it's one of thinkpads' electrical anomalies when elements detach from the board while (mis)handling the unit. Or something stupid like damaged ribbon.
All I can say is that it looks like something to do with LCD is shorting the circuit causing everything to die instantly.

I don't expect miracles from you guys. You can elaborate on the subject if you want. I, on the other hand, have one more screen to try and if that fails I'm not touching this one again until I get a reflow done on a mobo at some point.


Thank you

(me back to the good ol' A31 )

[RealBlackStuff]

For a reliable reflow you're in luck: see the sticky Graphics Resoldering Service Launched in UK and Europe thread at the top of the T4x forum.

[Troels]

Wish i could find a data sheet for the LTN141XA, but i guess one would have to ask Samsung for it. For XGA you only need 20 pins, because it is single channel. For SXGA+ you need the further pins. What could cause this is if Samsung decided to tie all pins from 21 to 30 to ground instead of being floating/not connected. That wouldn't work, if you T43 thinks (from the cable) that it must use pins 21-30.

[RealBlackStuff]

Wish i could find a data sheet for the LTN141XA

Take your pick: http://stock.adgic.com/AdgIC/stock/sear ... y=LTN141XA