Extending your laptop's LCD cable: FAQ

**Yuriy** · 06-19-2004, 06:51 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:
Inspiron 2500 LCD
2002 Saturn SL2 install
Freak show - 22 year old Nissan install

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, 03:35 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** · 06-21-2004, 12:32 AM

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** · 06-21-2004, 12:41 AM

...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, 10:55 AM

This is a great thread. Thanks for the info!

Rich

**eCar™** · 06-21-2004, 11:16 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, 12:23 PM

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, 06:30 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, 06:42 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, 10:23 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.