Has anyone hacked up a laptop to use the LCD by itself?

G

Gh0st

Limp Gawd
Joined
Aug 3, 2001
Messages
131
I have an old junk laptop that wont turn on anymore but the screen still works. How tough would the laptop screen apart and use it as a monitor? I'm guessing there are just a few wires that correspond to a VGA plug? Could I just get a ac/dc converter from radio shack to power it?
 
Depends on the design of the laptop. My old Vaio's panel had like 30 wires that went to it since the controller was part of the motherboard. In that case, you'd have to make your own LCD controller to control the inverter, backlight brightness, pixel mapping and voltage, and also handle the incoming signal from the video subsystem of whatever's driving it.

In that laptop's case (no pun intended), getting to the display was as easy as pulling the keyboard and speaker bezel, then removing the four or so screws holding the display and hinges to the bottom. The one in my Toshiba that I have now requires taking the whole damn bottom apart to get to the hinge screws. Then you still have to take the motherboard out to unplug the display. So, YMMV
 
Hmm, this is an old Compaq. I'll have to break it open tomorrow and take a look
 
All of the plugs on a laptop screen are usually proprietary plugs and connectors. It's gonna take a lot of electrical engineering and soldering skills to reverse engineer a laptop LCD monitor for use as a separate monitor.

It's been done before but I doubt you'll want to go through the hassle and time of doing so:
http://www.hardmac.com/news/2006-03-28/#5307
http://forum.macbidouille.com/index.php?showtopic=102465&hl=interface (French Forum link for above)

Took the guys above two years to do that.
 
If you are lucky, it will be a standard LVDS connection which you can then use on some ITX boards that have a LVDS port or LVDS expansion module (make sure to get the panel & board datasheets to make sure the signal wires are correctly hooked together)
 
"Old junk laptop"? I don't think it's worth your trouble. Get a shiny new 22" for $200 and call it a day.
 
You are close. At least about the wallwart being required. The few wires aren't as simple as you'd think:

http://excel-display.com/ex104dvbal.html

You would need a rather large and complex control board to convert the laptop LCD's connection into a standard VGA connection + a wall wart to power it.

There are several DIY projects w/ schematics and PCB designs you can get on the internets if you search for them. This was an area I was interested in before (as I had access to a nice 1600 x 1200 15" Laptop LCD). From what I've found there is no premade box you can buy. I believe Make had an article on their website about a group of people who made it work (french instructions if I remember).

If you know how to read a schematic and datasheets and have a good .1mm soldering iron tip I'd say give it a search and a try. I also remember seeing a laptop-LCD daughter board adapter for a Mini/Nano/Pico-ITX motherboard. You can pick up one of those but it'd cost you $200-300 for the board itself + the daughter board + ram + a HDD + case + PSU adapter.

Cheers,
-robodude666
 
zzz said:
"Old junk laptop"? I don't think it's worth your trouble. Get a shiny new 22" for $200 and call it a day.
Click to expand...

I don't need another monitor, I figured if it was an easy project it might be nice to have another smaller LCD around, but its not sounding like its so easy
 
robodude666 said:
I believe Make had an article on their website about a group of people who made it work (french instructions if I remember).
Click to expand...

The link I had in last post is that French thing you're talking.
 
You would need a rather large and complex control board to convert the laptop LCD's connection into a standard VGA connection + a wall wart to power it.
Click to expand...

I disagree, this can't be too hard as laptops use the same/similar video chips to desktops and almost have
vga ports, why wouldn't a laptop lcd be vga too.....I agree you would need to power it and rewire it's connection. I have an old Compaq Armada to play with....and will investigate.
 
HemiRick said:
I disagree, this can't be too hard as laptops use the same/similar video chips to desktops and almost have
vga ports, why wouldn't a laptop lcd be vga too.....I agree you would need to power it and rewire it's connection. I have an old Compaq Armada to play with....and will investigate.
Click to expand...

VGA ports and LCD output on the laptop are two different things. Go back to your desktop LCD comparison. You may be able to connect a VGA cable to your LCD, but that doesn't mean the panel itself uses VGA signaling. The control board inside the display converts the VGA signal into one that the panel requires to operate. In most laptops, that control circuitry is part of the main system board so that manufacturers can reduce parts count and design complexity. The panel then gets it native (proprietary) signal straight from the motherboard.
 
HemiRick said:
I disagree, this can't be too hard as laptops use the same/similar video chips to desktops and almost have
vga ports, why wouldn't a laptop lcd be vga too.....
Click to expand...

Quoting from a different site:
To plug any recent laptop LCD screen into a ISA/PCI/AGP/PCI-E/whatever VGA port would be impossible, as Mallegonian stated.

VGA video cards have their video signal converted from digital to analogue so that the signal may be interpreted by the CRT monitor. Some of the original LCD screens converted the analogue signal back to digital to produce the image.

Newer LCD screens, and video cards, do away with the analogue change. The signal is kept digital and sent that way to the screen. Early laptops were analogue as well but most - including most likely yours - are all digital.

So to plug an LCD into the VGA port wouldnt work, however to be plugged into a DVI port would work. Not only that, but the video card will have to be able to talk to the LCD properlly. In terms of refresh rates, resolutions, colour depths, and so on.

Furthermore, connectors on LCD screens for laptops are highly proprietary. A DVI connector on a video card will always have a set number of pins, ... or holes. And each of those always has the same signal. The LCD connectors are different from model to model. Not to mention that connector also carries power for the cathode/flurescent light that illuminates the screen.
Click to expand...

Or pretty much what ryan just said.
 
I researched using a 1080p laptop panel for a projector system and it is possible but not worth doing.

A number of manufacturers make controllers capable of driving most of the laptop panels (between them) but in some cases you need to send the panel to the controller mfr so they can fine tune the controller to it.
It is sometimes possible to use a generic configuration for all panels of a certain model in which case they can set it up for you before shipping.
The controllers can provide which ever connections you will need ranging from composite to HDMI, sometimes at extra cost.
A controller is not guaranteed to support any panel, you need to contact the mfr to find out.
There are a lot of panels and different revisions from numerous manufacturers.

The panels either need to work with the control board they are supplied with or another control board compatible with the panel and with firmware support for the panel.
The LCD controllers in laptops cannot be separated from the main system and do not allow external connection.


Most laptop LCD panels are TN panels utilising only 6 bits per colour with dithering to extend the range.
Modern displays are extending into 10, 12 and even 16 bits per colour so I wouldnt put much money into doing this project.
The display quality will never be any better than when it was used in the laptop.

This will be a costly project, especially if you want it to support HDCP.
Its cheaper, less hassle and better quality if you buy a bigger LCD :)
 
Nenu said:
Its cheaper, less hassle and better quality if you buy a bigger LCD :)
Click to expand...

I think it's more that he has a perfectly good panel that could be put to some use rather than sitting around attached to a dead laptop.

OP have you considered selling it on eBay to some poor soul that has the same laptop with a broken screen?
 
You must log in or register to reply here.
Back
Top