LCD Repair?

[singbad]

Hi all,
when I press the power button my T30 shows a flickering, distorted coloured image on it's LCD for about 3/4 of a second, then it turns black. An external CRT monitor works fine, however. I can see the LCD backlight is still on. When I press Fn+F7 twice (i.e. I switch to the external monitor and back to LCD) the flickering colours flash up again for about 3/4 of a second. That makes me think the LCD is not completely dead.

Is this kind of failure a known problem with the T30 and is there a cure for it (other than replacing the display)?

Thanks for any help!

Singbad

[tracker]

Hi Singbad,

looks like you have the same problem as one of my T30 ,which was lcd cable assembly problem...try another lcd cable assembly.
It could be due to all the flexing of the cable ( from opening and closing of the lid )
that caused one of the signal carrying wires to be broken ...so lose synchronisation going to the lcd....hence strange effects!!!

What colour effect?...is it distorted ? It is too early to say if the mobo circuitry is bad until you try another lcd cable,
since you say an external monitor works ok, its highly unlikely the ati chip is bad on mobo ...

suggest you go for cable change first...
they are quite low cost in marketplace or ebay, whichever you prefer .

good luck !!!

Tracker

[ajkula66]

tracker wrote:

It is too early to say if the mobo circuitry is bad until you try another lcd cable,
since you say an external monitor works ok, its highly unlikely the ati chip is bad on mobo ...

The above statement is incorrect. There are two separate outputs from the GPU: digital for the LCD and analog for the VGA, and one can work perfectly well while the other is as dead as dodo.

I would highly suspect a failing graphic card, but would try out new LCD cable out first anyway.

Good luck.

[tracker]

wrote:
There are two separate outputs from the GPU: digital for the LCD and analog for the VGA, and one can work perfectly well while the other is as dead as dodo.

I would highly suspect a failing graphic card, but would try out new LCD cable out first anyway.

Good luck.

I agree ,thanks for pointing it out !

[singbad]

Thanks for your hints! I realized the port replicator has a DVI output which I found (somewhere) described as a "DVI pass-through" port. Does this mean it is directly connected to that digital GPU output?

I currently don't have a DVI monitor but I could ask a friend to try it.
Would it make sense to check if the DVI output works?

[tracker]

Could also take out keyboard (2 screws bottom ,centre ,with arrows ) press down on ATI GPU to see if bad solder joints are cause ,instead of cable bad

simple to do

[singbad]

Yes, I did that in first place. Re-seating and pressing connector or cable didn't make a change.

From a first glance through a pair of 3.5x magnifying glasses the socket looks well soldered. I'll take a 15x jeweler's lens later today to see whether I can spot any cold soldered connections by trying to move them with a pinpoint. I'm aware of T30 solder issues, I detected 3 loose contacts at the 2nd DIMM socket this way which I was able to re-solder sucessfully.

One observation from my trials: When I press Fn-F7 (twice) while I'm in the CMOS settings I can see the whole screen flashes up correctly and then immediately gets "crumbled" and fades away from right to left.

[singbad]

Today I got a T30 that doesn't power up any more but has a working display which I took for my good T30. It works so I think the graphics chip is OK.

I've put the bad display aside for now. If I can repair the bad mobo I'll give the LCD another try. Do I have a chance to rescue it?

Thanks for your help!

singbad

[tracker]

That's good
Now you have a spare parts source and you can confirm what is really bad, without guesswork
inverter or cable bad ,swap them...lcd panel also swap...people nornally just buy one from this site or ebay

Is this your hobby to repair T30 ?

[singbad]

Hobby?

Well, I came across the T30 when a girl friend asked me to score a cheap laptop for her on Ebay. I wasn't really looking for a Thinkpad, an Acer, Dell, HP or any major brand would have been OK. I was willing to spend about 150 $. I won the T30 auction at about 100 $. It had the memory-slot-2 problem which I could easily fix (I admit I have some background in electronics) and it was missing the HDD rail+cover kit (not the HDD itself). I found quite a few such kits on Ebay and I ordered one from China for about 7.50$, shipping included.

Later I did some market resarch and realized a T30 appears to be absolutely the best deal in that category. Many available, robust, excellent documentation and forum expertise available, cheap spare parts available. The only drawback I can see so far is the USB 1.1 ports. Any recommendation for a PC Card USB hub?

I've learned a lot about the T30 (thanks to this great forum!) and I admit I love it I don't need a 4GHz machine for typewriting or browsing the web. I've started bidding 100$ on every T30 I can get as more of my friends could use a good laptop. I'm just bored to fix their old scrap iron towers

I'm still improving/refurbishing my actual T30. The exchanged display has a strange effect. When it is powered it starts with a strong pink color bias but then within seconds the colors gradually turn to normal.

Is it the CCFL?

Best regards,
singbad

[RealBlackStuff]

Pink color is a dead giveaway for a dying CCFL.

[tracker]

i agree with you on the merits of T30 and this forum for getting great info....
T30 are good solid performers for most computing work and web surfing .

For USB 2.0 pcmcia ,i use one with VIA rev5 chipset ,made in china ,no brand name ,cheapo unit but fast , also is recognised by XP pro( plug n play) -no installation cd required

[singbad]

For USB 2.0 pcmcia ,i use one with VIA rev5 chipset

Thanks for the hint! You mean something like this?

I'll keep an eye on a PCMCIA CARDS with VIA chipset. But how do I tell it's rev5?

Best Regards,
singbad

[singbad]

I'll simply buy one to know.

BTW, I've disassembled the bad display cover assembly. The flex cable looks good. All 19 video lines are conductive, flexing and moving makes no difference.

Tomorrow I'll go into the LCD itself. I'm aware there's nothing to solder. Maybe I'll find some loose part. I've repaired a smaller LCD before by "ironing" a loose flex cable connection - with the soldering iron. If I can't save the LCD I'll take out the CCFL and use it for my good display, the one with the pink-start backlight.

Tracker, your sig sez "poweroff troubleshooting with trackers". Very interesting - have you done something with T30 boards? Mind to share your experience?

Best regards,
singbad

[singbad]

Seems I'm the only poster in this blog

I tried to repair my dead T30 display yesterday. I thought if I can't repair it maybe I could take out the CCFL as a replacement part for my working display that starts up with a pink color bias due to it's age.

I realized it's stuck somehow to the white backlight foil (why don't they use a metallic mirror foil instead of wasting 50% of the light?), I didn't dare to separate it. And after my experience with the dead display I did no longer want to disassemble my working one. I guess industry grade display assembly should be done under clean-room conditions rather than on a kitchen table.

BTW, I found a lose flat flex cable that once had been stuck (with conductive adhesive) to the glass substrate of the LCD. I re-seated it thoroughly (which was only possible because the right part of it was still stuck in place) and forced some pressure on it by inserting a piece of elastic foam between the glass pane and the bezel but it didn't do the trick. Adding more pressure by hand which usually shows some change didn't work either.

This leads me to the idea the fault is more likely in the PCB behind the LCD. What's that circuit for? It's not the line/column driver circuit, that's on the glass substrate. I only has about 30 output lines. And it has a trimmer resistor on it and an inductor like in a low power voltage converter. Any idea?

I'm quite new to the subject of LCD repair, not sure if I should go much deeper into it. I'd rather like to have a cheap source of compatible LCDs for the T30. Is there a compatibility list around?

Best regards,
singbad

[RealBlackStuff]

AFAIK, the T30 can only use these LCDs:
................ P/N........FRU
XGA Samsung ........... 11P8273 LTN141PE-L01
XGA Samsung 11P8289 11P8294 LTN141XE-L01
XGA ..Hitachi 11P8292 11P8297 TX36D37NC1NAA
XGA ..Hitachi 11P8292 11P8297 TX36D37VC1CAA

SXGA+ LG Philips 11p8290 11P8295 LP141E04 (B1)

[tracker]

you sure like a challenge ,

i just bought a working T30 lcd panel to swap out a problem unit.
They are cheap on ebay
Another complete T30 XGA lcd panel is for sale for USD45 on ebay

Because of work commitments have not been on the forum lately.

Yes i will share my knowledge on using trackers to look at t30 mobos .Just bought some faulty ones from this forum- marketplace. When i have time, this Xmas hols will take a look at them and post it.


Re : Usb 2.0 card..Yes,the one you found is worth trying. Mine has 4 sockets ,no cable attached,is a bit bulky ,does not power HD external drives directly.Other than that it works great with pen drives.Its fast and what i like is whenever i reinstall win xp ,i never have to worry about its driver. Can't live without it now

Have started a new topic on this ,check it out -have posted a link for you there

[singbad]

Thank you RealBlackStuff for the type IDs and part numbers. I spent a lot of time googling the universe for data sheets but I found almost nothing. At least I was able to extend your list a bit:

XGA LG-Philips LP141X12 (B1) .......... 150nit .... 11P8288 11P8293
XGA LG-Philips LP141X12 (B1) .......... 200nit .... 11P8218 11P8222
XGA Samsung LTN141XE-L01 ............ 150nit .... 11P8289 11P8294
XGA Samsung LTN141XE .................. 200nit .... 11P8269 11P8272
XGA Hitachi TX36D37VC1CAA ........... 200nit? .... 11P8292 11P8297
XGA? Hitachi TX36D37NC1NAA? ............. ? ........ 11P8292 11P8297
SXGA+ LG-Philips LP141E01 ............. 150nit ..... 11P8290 11P8295
SXGA+ LG-Philips LP141E04 ............. 200nit ..... 11P8219 11P8223
SXGA+ Samsung LTN141PE ............... 150nit ..... 11P8291 11P8296
SXGA+ Samsung LTN141PE ............... 200nit ..... 11P8270 11P8273

Unfortunately there's almost no T30 display for sale on Ebay Germany. It's more likely to get a defective T30 with a working display for under 75$ over here. But from what I've seen most defective T30 on ebay.de have dead LCDs though. The situation may be different in the US but most seller's international shipping rates are bizarre.

The idea behind my efforts is that I can get cheap displays of other laptop brands on Ebay, e.g. the Toppoly TD141TGCD1 that are compatible in terms of physical dimensions and data formats. I think I could solder adapters to the flat cable connectors since I've found most XGA LCDs of those days (2002) are following more or less the same scheme:

Power
Power
Ground
Ground
RED* (R0~R5,G0)-
RED* (R0~R5,G0)+
Ground
GREEN* (G1~G5,B0~B1)-
GREEN* (G1~G5,B0~B1)+
Ground
BLUE* (B2~B5,HS,VS,DE)-
BLUE* (B2~B5,HS,VS,DE)+
Ground
CLOCK-
CLOCK+
Ground
Ground or NC
Ground or NC
Ground or NC
Ground or NC

OK, they could use different coding schemes and color tables. I'm still into the data sheets...

*) EDIT:
I learnt the LVDS signals are multiplexed, distributed in time and space across the 3 data channels. So "RED" only means mainly red, "GREEN" mainly green and "BLUE" mainly blue . They've even integrated the synchronization and device enable signals into "BLUE". It appears to be some standard followed by different display makers.

LVDS Channel Interface Data Mapping Diagram

NC must be (or is spared for) h-sync and v-sync, ENAB = device enable
/EDIT

Best regards,
singbad

-- Heavily edited on Dec. 16, 2009 --

[singbad]

Why do T30 displays turn black out of the blue?

Has anybody ever repaired a T30 LCD?

What's that PCB behind the screen?

Who made this T15.5A-F LVDS-receiver chip?