T30 Display Replacement By Non-FRU LCD Panels

[singbad]

Hi,
I've successfully replaced several dead T30 LCDs by third-party makes found on Ebay for 1 EUR + shipping. I always had to solder a 20 to 30 pin adapter and they worked fine. The difficult part was fitting a 299 mm panel into a 298 mm frame. I had to remove the two antenna assemblies and the supporting posts around the screw holes in the sides of the display cover. I would have dremeled them off but I realized the case is made of a potentially hazardous fibre-compound material so I prefered using a small file and water.

I have replaced the T30 LCDs by Toppoly-TD141TGCD1, AU Optronics B141XG09 V3 and at least one more brand that I don't remember right now. Recently I came across a Chunghwa CLAA141XB01 which I chose for it's 20-pin connector. But it's 25mm wide, T30 LCD cables have ~21 mm connectors. Of course PCHub has cheap adapters for everything but each shipment is $16. So I soldered again but with no luck so far. The screen is divided into two areas of different size and shade, left side (~40% width of screen) pink, right side light blue.

Could it be a functional incompatibility? Clock frequency, timing or the like? Unfortunately my Chunghwa data sheet is incomplete.

Best regards,
singbad

ps
the missing name was Hyundai-BOEhydis HT14X19-100, fully compatible with the 30 pin models above

[Ville]

The thing is that lvds displays work in two modes. Single channel, wich is sequential and double channel. Both work with a single clock. Single channel means that every time the clock ticks, 3 color information packets, are sent by the gpu. on the dual ones, each time the clock ticks, 6 color packets are sent, but in an odd / even format. Since the t30 has a single channel for the display, and you are pobably connecting a dual channel display, the panel cannot correctly decode the color information, thus, generating the double gui effect.

I have seen a few pannels wich have a group of smd resistors, typically jumper ones (marked with a zero) al the way to 75 ohms, to act as a "jumper configuration" so that the display may work in single or dual channel. (Have done a few hacks myself)

On the other hand, it could also be that the timings of the lvds port are off with what the display is specting but that could imply that you must mod the gpu bios (embeded in the main bios) of your mobo in order to tweak the timings, but i dont think this is the case, otherwise you would not have this mirror effect.

In any case, the simplest solution is always recommended, i would suggest, get a new display that is compatible out the box with the lappie and save the otherone for a cool hack! (like a multitouch display or something else)

Salut!

[singbad]

Hi Ville,
thanks for your your reply! Sorry for my delayed follow-up, e-mail notifications still don't work for me.

I didn't know about dual channel mode but this could explain the effect. The guy who sold me the display said his old laptop had a set of DIL switches to allow the use of different LCDs. That points to it too. I'll have a look at the PCB on the LCD, maybe I can spot the resistors you mentioned.

I've been sniping some cheap LCDs on Ebay. I found I must have a 20-pin 25mm JAE connector. The Thinkpad T30 display connectors are 22mm but at least the pinout will match. The corresponding 25mm connector is hard to get in Europe. But the LCDs often come with their original cables.

During my adventures in microsoldering I found I need an additional cable rather than just the adapter since the IBM cable is to short and sits in the wrong place.




I found some LCD cable converters at PCHub [but as far as I can see they're all the other way].
[I need one that converts the opposite way,] 20 pins 22mm to 20 holes 25mm, 100mm cable length.

[EDIT]
The LCD cable converter at PCHub appears to be exactly what I need. Now I must find out how much they want for shipping (and how many I can afford )
[/EDIT]

[I hope I can get 25mm 20-holes connectors at least like e.g. JAE FI-S20S. JAE makes an LVDS Development Kit:
In order to help support prototype development JAE has introduced a range of FI kits which consist of 2 x crimp socket housings with pre-crimped 300mm leads. The number of leads included is appropriate to the number of contacts in the housing.


Seen for $14 at Digikey, Farnell and RS. I would need to mix two kits, one with 22mm and one with 25mm connectors. And I'll have to make sure both types of sockets will fit into both housings. Fine pitch connectors usually have thinner pins and sockets.

Has anybody seen something similar for less? ]

Best regards,
singbad


EDIT:
oops, I must have been confused last night, the above is exactly what I need, not the opposite.
[edited: ignore the blue parts]

[singbad]

.

[paride]

What an interesting thread, I'm trying to do the very same thing!
I own a Thinkpad X60s with a 12.1'' XGA (1024x768) CCFL LCD panel and I've recently got a brand new 12.1'' SXGA+ (1400x1050) LCD panel made by Toshiba (model LTD121KM2M, you'll easily find some specs by googling this code).

I'd love to have that resolution on my laptop, so I'm trying to replace the original LCD with the new one. The problem is that the new screen has a 30pin connector, while X60s uses a 20pin connector (I think it's the 22mm version); the two connector are also not perfectly aligned. I ordered an adapter from pchub.com, I hope it will be the right one.

I'm a bit confused about the single channel/dual channel issue. How can I tell what mode is supported by my laptop and by the LCD screen?

singbad: can you confirm me that you made some 30pin screens work on laptops with a 20pin cable? Where did you find the first connector you posted a photo of? I mean this one

http://ftp.nuclear.free.fr/img/LCD/20to30pin.jpg

Any suggestion is welcome, wish me good luck!

[kereoz]

Hi Paride,

I'm planning to do the same thing, I first planned to order a Boe-hydis HV121p01-100 but those are a bit expensive and quite rare these days...
The LTD121KM2M seems like a good option too and it is actually cheaper.
Have you sorted the single/dual channel problem yet ? And what about using a 20/30 pins cable ? Did you get it working at this stage ?
And most important : does it fit in the lid of the x60s ? As this one is really thin, I'm not sure about which LCD panels would actually fit in there...

Cheers,
Kereoz

[paride]

Well, bad news: it didn't work.
As I turn on the computer the LCD panel turns all white and nothing is displayed. I think I won't have a lot of time to dig in it in the future, I think I'll just use that SXGA+ panel for something else or eventually sell it on ebay. It has been a little delusion anyway. Let us know if you'll have better luck.

[RealBlackStuff]

Try and get the datasheets of those LCDs.
I'm going to install a wide-angle LCD from an X41-Tablet into an X31 machine.
You need to turn the LCD-cable 180 degrees on the back, because connections are reversed.
I mention this, because that might also be the case between X60s original and replacement LCD.

See also http://forum.thinkpads.com/viewtopic.ph ... 38&start=0

[paride]

I really can't find the data sheet, but I'll try to understand if the wiring is reversed and let you know.
Thank you for the hint!

[paride]

I tried to connect the laptop's 20pin cable to the 20pin-to-30pin converter twisting the cable for 180deg but it didn't work: nothing appears on the panel. I don't think I'll dig into this more.

[singbad]

Hi,
sorry for my late follow up, I wasn't notified on new posts in this thread.

@parid: I made this little adapter by myself and yes it worked, at least as a proof of concept. You can order 20-to-30 pin cables at PCHUB. I've ordered ten 20-to-20 pin LCD cables from them. I haven't yet checked them all but one had two neigbouring wires shorted by a tiny bead of solder. Check for correct wiring and short circuits first.

I haven't seen a reversed pin order on LCD connectors yet. All appear to follow the same scheme (starting from pin 1):

- supply voltages and ground

- EDID signals and clock (on 30-pin LCDs only)

- LVDS video signals and clock

- spare pins


This is my 20-to-30 pin scheme:

Code: Select all

[size=85](LG-Philips LP141E04)            Toppoly TD141TGCD1
HIROSE DF19K-20P-1H Connector    JAE FI-XB30SR-HF11 Receptacle / FI-X30H Connector
--------------------------------------
                          +------|  1 VSS  Ground
                          |    +-|  2 VDD  Power supply +3.3 v 
--------------------------|-   +-|  3 VDD  Power supply +3.3 v 
.1 Power                  | |  | |  4 EDID Power 3.3V 
.2 Power                  | |--' |  5 NC
.3 Ground                 +-|-   |  6 EDID Clock
.4 Ground                   |-   |  7 EDID Data
.5 D0- (R0~R5,G0)-          |----|  8 Rin0- -LVDS R0~R5,G0
.6 D0+ (R0~R5,G0)+          |----|  9 Rin0+ +LVDS R0~R5,G0 
.7 Ground                   |----| 10 VSS   Ground
.8 D1- (G1~G5,B0~B1)-       |----| 11 Rin1- -LVDS G1~G5, B0~B1 
.9 D1+ (G1~G5,B0~B1)+       |----| 12 Rin1+ +LVDS G1~G5, B0~B1 
 10 Ground                   |----| 13 VSS   Ground 
 11 D2- (B2~B5,HS,VS,DE)-    |----| 14 Rin2- -LVDS B2~B5 DE Hsync Vsync 
 12 D2+ (B2~B5,HS,VS,DE)+    |----| 15 Rin2+ +LVDS B2~B5 DE Hsync Vsync 
 13 Ground                   |----| 16 VSS   Ground 
 14 CLOCK-                   |----| 17 Clk_IN- -LVDS clock input  
 15 CLOCK+                   |----| 18 Clk_IN+ +LVDS clock input  
 16 Ground                   |----| 19 VSS  Ground     
 17 Ground or NC             |----| 20 NC
 18 Ground or NC             |----| 21 NC 
 19 Ground or NC             |----| 22 VSS  Ground     
 20 Ground or NC             |----| 23 NC 
 ----------------------------     | 24 NC 
                                  | 25 VSS  Ground     
                                  | 26 NC 
                                  | 27 NC 
                                  | 28 VSS  Ground     
                                  | 29 NC 
                                  | 30 NC
                                  --------------------------------------
  [/size]

BTW, when I ordered 10 20-to-20 pin LCD cables they gave me a good discount so the price dropped to $5.12/pc including shipping.

Best regards,
singbad

[paride]

Thank you for your reply. I own a 30pin-to-20pin adapter from pchub. I actually own two: a straight one and a bent one, as when I bought them I was confident one of them would have worked but I didn't know which one fit better. It turned out none of them works. I just tested with a multimeter and they seem wired the same as your scheme.

I'll keep the adapters for future experiments but I think this one failed, unless I get some good suggestions in the very next days...

[paride]

I haven't seen a reversed pin order on LCD connectors yet. All appear to follow the same scheme (starting from pin 1):

- supply voltages and ground

- EDID signals and clock (on 30-pin LCDs only)

- LVDS video signals and clock

- spare pins

Well, I noticed a little difference: on my adapters the EDID pins on the 30pin side are not wired to anything, while on your schema the EDID Clock pin seems grounded. I don't know if this could matter...

[singbad]

EDID is useless in laptops (and thus unconnected) since the type of LCD in use is well known to the manufacturer and usually remains unchanged over the laptop's lifetime.

[singbad]

I've replaced an original T30 LCD by a Hyundai HT14X14. It shows VGA resolution on startup, during BIOS setup and also after the system has booted. Everything is displayed about twice as big while the original LCD works OK.

The same thing happened with a Samsung, can't remember which one. I tried different LCD makes before that used to work well. Could it be the effect of single channel signals on double channel LCDs? I thought a double channel LCD wouldn't synchronize at all on a single channel signal since the coding/decoding scheme is completely different.

Can I set the ATI Mobility Radeon 7500 output to double-channel mode? Perhaps I'd have to hack the BIOS settings and change the OS drivers? Or is it changed by a hardware signal, like a pull-up or pull-down pin?

Best regards,
singbad

[singbad]

SOLVED!

Forget about double channel mode. After trying a couple of LCDs known to work with the T30 I discovered that instead of the appropriate XGA cable I had been using an SXGA cable (FRU 27L0707) all the time. I changed the cable and all my LCDs work. Now I can go on repairing IBM displays using cheap LCDs from the Electronic Bay.

[EDITED]

[singbad]

I'm still wondering: in which way do SXGA and XGA cables differ?

One explanation for the observed effect could be the integration of hard wired information in the cable, like the monitor identification pins in analog VGA connectors. Does the cable tell the graphics chip 'I'm XGA' or 'I'm SXGA'?

[Frobe70]

EDID is useless in laptops (and thus unconnected) since the type of LCD in use is well known to the manufacturer and usually remains unchanged over the laptop's lifetime.

As far as I know this is true for all old Thinkpads prior to T60/X60/R60-series and newer which all use EDID instead of cable identification/selection of panel resolution.

[kereoz]

I tried to connect the laptop's 20pin cable to the 20pin-to-30pin converter twisting the cable for 180deg but it didn't work: nothing appears on the panel. I don't think I'll dig into this more.

Hi Paride,

sorry for my very late follow-up.
The LTD121KM2M appears to be using a "standard 30 pin connector". Why would it be any different from a Boe-Hydis HV121P01-100 ? Both have a 30 pin connector anyway, and I doubt the pin assignment is an issue.
I suspect your problem is somewhere else. Could you give more details about what happens when you try it ?

Did you upgrade the BIOS first ?
You might just get nothing if your BIOS cannot set the right modes.
You might also want to try running a Linux or whatever OS including Xorg, as it automatically detects the modes of your screen.

Kereoz

[paride]

Hello kereoz,

sorry if I reply so late.
When I start the compute with the new screen it just shows up all white and I see nothing on it. On the background the operating system (Linux) starts. Xorg doesn't start automatically but the high resolution concole (KMS) does, and still I see all white.

[jayshreelaser]

Hi...... All of are
i want to know pinout or how to interfacae Hitachi lcd TX36D87VC1CAA to vga card
any 1 help me...
thnx
Nishant