Extending your laptop's LCD cable: FAQ

Yuriy · 06-19-2004, 05:51 AM

MODS: Please make a sticky out of it.

Here are a few quick questions and links about extending your laptop's LCD cable/ribbon:

Q: Can I extend my laptop's cable?
A: Yes, it's been done a number of times!

Q: Will the signal be unusable if I make my wire too long?
A: No, the signal will be OK. As long as you keep the INVERTER<>BACKLIGHT cable the original length.

Q: What is an INVERTER and what does it have to do with the above question?
A: Inverter is a small board that usually sits right next to your LCD (inside the LCD casing). It apmlifies the signal coming from your laptop's motherboard into a stronger signal used to power your backlight. The longer you make the cable between the inverter and the backlight the darker your backlight will become. That is why it is important NOT to extend the INVERTER<>BACKLIGHT cable. You can still extend the LAPTOP<>INVERTER cable.

Q: What is the optimal length of the laptop LCD extension cable.
A: I don't know really. Mine is 1 meter long (about 3 ft). It works fine, although I sometimes get some barely noticable interference. Make the extension as short as possible and you will be fine.

Q: I have a flat ribbon cable running to my LCD. How do I extend that?
A: Visit this link: http://www.groupsrv.com/science/viewtopic.php?p=267233
And it appears that you can also buy a custom extension here: www.molex.com

Q: I have a lot of small but separate cables running to my LCD. How can I extend them?
A: Buy an LPT (printer) extension cable at your local computer store. Chop off the ends. Inside you will see around 50 small cables, each one will have it's own unique color combination (two stripes of different colors). Use those to extend your LCD cable.

Q: Can I see some examples of extended laptop LCDs at work?
A: Visit the following threads:
http://www.mp3car.com/vbulletin/showthread.php?t=27744
http://www.mp3car.com/vbulletin/showthread.php?t=27807
http://www.mp3car.com/vbulletin/showthread.php?t=27853

Q: Do I really need to solder all those tiny cables together?
A: No, I never use soldering unless I really need it (to extend my factory stereo's volume controls for example). You can connect the wires by hand. Remember to use sticky electrical tape to isolate the connections properly or you will be in big trouble.

More questions - ask here!

choyak · 06-20-2004, 02:35 PM

I would recommend soldering for ANY electrical connections made. If you just twist the wires and tape, there is a chance that the connection will fail over time. Soldering guarantees no failure if it is soldered correctly. Also if it is not soldered, there is a chance that the connection will fly apart.

Yuriy · 06-20-2004, 11:32 PM

Good point, however when you have to solder 47 x 2 = 94 wires it can take a while

But you're absolutely right.

gospeed.racer · 06-20-2004, 11:41 PM

...but when you done, and one loosens up, which of the 94 was it? And is it worth redoing it all? Be safe...even if you dont do it yourself, you still should recommend it.

srcstc · 06-21-2004, 09:55 AM

This is a great thread. Thanks for the info!

Rich

eCar™ · 06-21-2004, 10:16 AM

So, when you say that I can't make my cable too long, do you really think that I could get 4 meters without a problem?

Does it matter what type interface is between the controller and LCD? Or can all types run "unlimited length" cable?

Yuriy · 06-21-2004, 11:23 AM

Quote: Originally Posted by eCar™

So, when you say that I can't make my cable too long, do you really think that I could get 4 meters without a problem?

Does it matter what type interface is between the controller and LCD? Or can all types run "unlimited length" cable?

The longer the cable gets the more interference you will have. By interference I mean weird lines going across your screen, like on a TV with bad reception, and some character/shape distortion.
I doubt that you can get 4 meters without a problem, I was saying 4 feet (1.33 meters) and I do have very minor signs of interference.

I've heard that there are two types of interfaces in laptop LCDs, but I beleive that both are extendable.

Squid Bait · 10-25-2004, 05:30 PM

I just got my hands on a free Dell Latitude CP, and am looking to make myself a carputer on the cheap. I have hit the first of several snags... getting the LCD away from base. The inverter is in the lcd casing, so that's not an issue, but the cable is the copper on plastic ribbon variety and far too compact for me to solder. Idealy I could find or make and extension cable for the end of the cable where it meets the MB. I have yet to identify this connector though...

http://law.uark.edu/junk/bob/plug1.jpg
http://law.uark.edu/junk/bob/plug2.jpg

If anyone here can tell me what it is, and more importantly, where to find one, I would be quite happy indeed.

Thanks

Ricky327 · 10-25-2004, 05:42 PM

Oh those Dell CP...

The LCD cable/connectors normally goes wrong in them...I have changed quite a few in them.

The plug that goes into the system board is soldered on a PCB. If you carefully remove the foil you should be able to get access to this PCB contacts.

From there maybe you can solder the extensionwires directly.

Check dells website for part number am sure it is there somewhere. Just be aware that there a few type of this cables depending on the screen you have installed.

99bravada · 08-15-2005, 09:23 AM

I've extended a 12.1 24bit TTL LCD (from the Kiosk PCs) over 6 feet via a 50-wire IDE cable (unshielded). No interference, and like Yuriy said, the trick is to extend the low voltage side of the inverter, keeping the actual inverter as close as possible to the screen.

alis · 09-28-2006, 01:26 PM

Hi
I have dell I8600 and want to extend its LCD cable but without cutting it.
I need 2 additional connector and a cable to do this, but i don't now what kind of connector should I buy?

I have 2 number, these are cable part number.
2C415
dc025040800
and this is its pic:
(The connector that I need is at the bottom).

You can find more pic here:
http://www.bay-wolf.com/8500video.htm

Is there any one to help me to find the appropriate connector for it?

thor918 · 01-15-2007, 07:37 PM

hi there. I finaly finished my lcd extending project.
I wanted a lcd touchscreen (lifebook b2131) put on a lcdarm. From there I could controll a music player.

What I learned from extending my lcdcable:
* try to find points on PCB that are bigger and easier to solder on
* don't try to solder on the lcd cable PCB
* use cables that are suiteble. I used a network cable first(that was what I had availeble at first..), but got interference. Then i used high quality kvm cable that had screen/mouse/keyboard cable molded togheter. everything was shielded. it even had three shielded cables inside a shield. using this cable I had the lcd controller, touchscreen controller and inverter (inverter pcb is built into the screenpackage. it sits close to the lcdscreen, so in my case it was the low voltage wires that where extended) on each of their own cable that was shielded from each other. I can 't see any interference on the screen using my 1.5meter cable

I also have plans to extend the powerbutton, so it is located in the plastic of the screen..
(I have the pins located on the motherboard if anyone is interested)
and wouldn't it be cool to also integrate the laptop mouse thing into the screen?? hehe (I mean the mouse that is integrated into the laptop normaly)
not sure about the last idea because I plan to have to OS working without the mousepointer.

@Yuriy: how did you get winamp so big?

rsema · 04-10-2008, 06:09 PM

Hi everybody...I too need to extend my cable, but my problem is a little different. I have an eight inch touchpanel that I am using in my dash with my laptop about 10ft away...this was not a problem untill my vga port on my laptop went out, so I want to make the touchpanel my primary monitor by extending the cables from my mother board to my the screen...I was wondering if I could do this length and how i could match up the wires since it is two different circuit boards...luckily i dont think i have to worry about the inverter/backlight cable because that is already on the touchscreen....where could i find out how to do the conversion from my motherboard to the lcds control board...i have a hp dv4230us laptop by the way...thanks for all the help in advance

fparri · 05-01-2008, 04:04 PM

I have recently been given an old IBM Thinkpad X40 laptop as a gift, since it had a broken lcd display (it got crackled). The pc works, perfectly, though, when connected to an external monitor.

Now, I'd also like to try and change the LCD with another one, since I found a Thinkpad X41 also broken at work, but whose monitor works perfectly.

The monitor connectors are the same and when plugged the new X41 monitor works perfectly and I can work with the pc. The problem is the ribbon cable used to connect the monitor to the inverter is a pair of centimeters too short, so I can't close the laptop

Here's a picture:

Do you know if it's possible to expand it or if it's possible to buy a longer one? Is there any other solution you might know?

Thanks a lot in advance,
Fabio