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Can I turn my lcd laptop monitor into a desktop monitor?
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Johnathon
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19. March 2005 @ 02:20 |
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Prisoner my apologies, I had not thought properly about your comments earlier. You are right, if you want to hook one up to a desktop then the easiest way would be to mutilate an existing PCI video card and marry the laptops exiting FDPlink circuitry to the graphics adapter (sounds a lot easier than it would be). Personally I want to be able to use my old LCD's with my latest laptop and hence need to be able to plug it into a VGA port (wish it had a DVI-I/D port).
I have now found numerous discussion on the internet about this topic and here are lots of links to look at:
Controllers with Prices
http://store.earthlcd.com/s.nl/c.318770/sc.7/category.5/.f
Discussions
http://www.techwarelabs.com/community/viewtopic.php?t=1313&postdays=0&postorder=asc&start=0
(17 pages of discussion - the later pages interesting but no real "meat")
http://www.pcclub.com/forum/arcmessageview.cfm?catid=28&threadid=2611
(this guy bought the controllers etc from above link and has it working with images - cool but expensive!)
http://www.forumplanet.com/planethardware/topic.asp?fid=3710&tid=1467022
(Another discussion)
http://old.area26.no-ip.org/?section=hard&project=vgalcd
(This guy built his own circuit for a TFT screen and it kinda works - well done but old analogue TFT not same as modern digital LVDS LCD)
Education on TFT and LCD technology
http://graphics.tomshardware.com/graphic/20041129/index.html
(highy recom. read the whole series of pages on DVI especially DVI connectors as has wiring pin-out)
Alternatives
http://www.globalcomputer.com/applications/refurb/refurb_slc.asp?page=3&CatId=12&category=Monitors
(Just to keep things in perspectives - refurb. LCD monitors at rock bottom prices from trusted reseller Systemax)
My current thoughts are this, LCD Monitors are different from LCD Displays in Laptops in one big way. Laptops don't contain the TMDS circuits (Tx/Rx - refer to http://graphics.tomshardware.com/graphic/20041129/tft_connection-02.html for more info).
This is probably because everything is nicely contained in a small package and the cables/data do not need to traverse any sort of distance like it would for an external monitor. Hence the GPU output does not need to be converted to a serial data stream from being parallel and back again (for RFI/EMI reasons).
This is a good thing as it supports Prisoners suggestions although a a power source/supply for the inverter would need to be arranged (+12 volts with approx min. 1.0amps - I'm guessing) but the PCI card should be able to supply the 3.3volts to the FPDlink circuits.
Of course in my particular, case none of this really helps as I need a USB 2.0 adapter with a DVI output (I have found the Sitecom.com - CN-105 - USB 2.0 to VGA adapter but it is VGA/analog). If I could find one of these then I could "marry" old LCD controller (FPDlink circuitry) I pulled ouy with the old LCD screen.
Whatever the outcome this investigation has so far been very educational.
This message has been edited since posting. Last time this message was edited on 19. March 2005 @ 06:33
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flipf0nt
Newbie
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23. March 2005 @ 17:21 |
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so i think i understand the incompatibilities between vga and dvi. I recently have had an old lcd that i was going to use as a monitor. I had all but given up on it until i found a 3d card that supports dvi. Its a geforce 5200 i think, 128 mb 8x with dvi ( 30 pin connector). Laptop lcds are 20 pins which got me stumped. is there a way i could convert a 20 pin to 30 pin? Heres a link to laptop lcd pinouts http://www.pinouts.ru/data/dfp_pinout.shtml
is there still a possibility i could get this to work? i want to build a projector using the lcd, and im hoping this works
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Prisoner
Suspended due to non-functional email address
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24. March 2005 @ 11:07 |
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flipf0nt, I think you miss understand. The more I read about this I don't think you can take the cord from the LCD and add a 30pin plug to it. The LCD needs a bunch of stuff that the computer used to give it and the normal LCD screens have.
I am not a number
I am a Free Man
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Johnathon
Newbie
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24. March 2005 @ 12:57 |
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flipf0nt,
Prisoner is right. It's just not that simple. The here is flow of connections I imagine any PC/External Monitor combination would require.
I know this is really hard to follow but its difficult to type concise relationhips using this interace.
CPU ... Graphics Card/Chip ... Graphics Transmit Interface (DVI or VGA)
<< CABLE either VGA OR DVI>>
... Graphics Receive Interface (DVI or VGA) ... LCD Controller
<<LVDS CABLE to LCD.
<<CABLE to INVERTOR>>
... LCD Inverter <<< SWITCHES FOR POWER AND BRIGHTNESS ETC TO INVERTOR (OR VIA LCD CONTROLLER IN MOST CASES ON TYPICAL LAPTOP)
Basically what you are missing in your case is the LCD controller which converts the signal from DVI (which is a particular type of interface) to LVDS which is the type of signal most LCD's are expecting.
Please also note that the DVI cable is not providing misc. necessicary functions such as an ON/OFF switch and brightness etc. At least it is not as far as I know. My understanding is that this is always part of the unique and specialised circuits within a laptop or monitor and specific to how the manufacturer wants to implement them - i.e. hardware or software etc.
Hope this helps.
Johnathon
This message has been edited since posting. Last time this message was edited on 24. March 2005 @ 12:57
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masona14
Newbie
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2. April 2005 @ 16:58 |
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I have an old lcd screen from a toshiba portege 3010t and i was wondering if it is possible to make it work with a standard monitor cable?
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achilles0
Newbie
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2. April 2005 @ 19:46 |
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no you would need a controller board.
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masona14
Newbie
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2. April 2005 @ 20:05 |
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Which board would i need
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achilles0
Newbie
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2. April 2005 @ 20:11 |
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well i had a similar idea but the problem was the more popular companies only make controllers for big lcd's so you could first call up the company that makes your lcd and ask them for compatible controllers and if the dont give you any answers (they most likely wont) you ask them to email you the manual to your lcd. When you know all of the exact specs you can begin your search on what u need. Dont forget that LCD's dont run on a DC current, they need AC so if your controller bord doesnt have one you might need to get an inverter. You should contact someone that may know about your monitor like the guyz at EarthLCD.com they know exactly what you need.
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masona14
Newbie
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3. April 2005 @ 08:28 |
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My video card has a port to use an lcd monitor is it possible to wire that to the laptop lcd?
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achilles0
Newbie
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3. April 2005 @ 14:50 |
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hmmmm i havent heard of that and if it is true it wouldnt make any sense because the vidio card is analog and the lcd is a all digital signal...do you have any pics?
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LaptopLCD
Newbie
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11. April 2005 @ 13:12 |
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Hiya.
Would having a graphics card with a DFP connector make you not need the LCD controller ?
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DeanMan
Newbie
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18. April 2005 @ 11:51 |
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OK guys here it is, THE GUIDE ON HOW TO CONVERT A LAPTOP LCD INTO A REGULAR COMPUTER MONITOR. I'm a physics grad student and I have been working on this for a few weeks now. Here's what I've learned. In newer TFT LCDs (the only ones worth your time), a new standard known as FPD-link is used. Basically, this bottles all the video info down into 8 wires using a form of low-voltage differential signaling (LVDS). Those 8 wires are all it takes to run an LCD.
First off, there isn't a "twisting wires together" way of doing this, but there are some myths. I keep hearing people say, "you need a driver", or "you need a controller", well they are full of it. The driver chip is built into a small circuit board on the LCD itself, so you already have it. And you don't need to spend $200 on some PCI video card with 2 MB of video memory to drive your LCD. All you need to do to make an LCD work as a desktop monitor is feed the proper signal into the driver chip you already have. Normally the LVDS receiver does this, but you don't wanna mess with LVDS, in fact I wouldn't have a clue how to multiplex the signal into FPD-link format aside from using a LVDS transmitter.
So, the way to do this is (theoretically, I haven't done it yet) to de-solder the FPD-link reciever chip, and solder your inputs where its outputs would have been. As for the video, it will sound difficult, but its actually easy. You need to make a few seven (or maybe eight in some cases) bit Analog to Digital Converters (or ADCs, note: my Hitach screen from a Dell Inspiron 7000 uses 7 bits for each color). You will need an ADC for each color (3 total). Then you just need to figure out which clock speed your driver chip needs (I believe this is called the dot-clock, and I think its usually 85 MHz) and set your ADC sample frequencies accordingly. (In my case the sample frequncy should be a "divide by 8" (industry term) since there is seven bits and a "dead time" where no data is read), Oh, and you will need a phase-locked loop (PLL) at the proper frequency to generate the master clock pulse for your converter.
If you guys want a schematic do me a favor and find me the datasheet on my LCD driver chip. I don't even know who makes it. its an 80-pin square probably LFQP, and labled as follows....
Tcon-16.1-F
SLA4028F2C
V99100289
JAPAN
Here's the deal, If I can ever get the datasheet that gives me the timing diagram for this driver chip (many other driver chips must be compatable as there are only a handfull of LVDS chips used), I can make the converter. I'll etch my own Printed Circuit Board (PCB) and solder up the everything (which will most likely be surface mount :( ). If it works, I'll post a tutorial, and most likely sell a few converter boards to the brave ones (don't worry, I'm not out to become a millionare from this). But my ultimate goal is to incorporate some extra video processing and get S-video hooked up (although component-input may be easier, I don't know). This would basically turn a laptop LCD into both a computer monitor AND a TV. In the final stages I plan on redoing the electronics to split the video onto four LCDs, making one big TV I can hang on the wall (with a small line down the middle :( of course).\
And I should be able to incorporate an LVDS transmitter chip on the board (eventually) which would mean: no removing chips, and just 8 wires to connect. These are the ones I'll end up selling
Anyways don't let people tell you it can't be done. I'm gonna do this for under $30, just watch. I'll post the schematic and pictures (of the LCD working, and the wiring) once its done.
Email Dneuf2@hotmail.com if you have the crucial datasheet or have questions. I don't mind answering questions, but please see if google has your answers before you ask me.
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Prisoner
Suspended due to non-functional email address
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18. April 2005 @ 13:49 |
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Cool!!!!
I can't wait to see if you get it working. I have been on hold with my project. As my actual research and work gets in the way of this fun. The aproach sounds logical, So I think it might work. Good luck.
By the way posting you e-mail address in full is a really bad idea. If you do want to post it use some random keyboard keys and tell people which to avoid. Spy ware on the net will send you e-mails like crazy soon.
I am not a number
I am a Free Man
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DeanMan
Newbie
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19. April 2005 @ 09:28 |
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Thanks for the tip, but my hotmail account is just for the purposes of stuff which could potentially result in spam, so it is flooded with it anyway. I still scan the titles of messages that make it through all my filters, and I have two other addresses which I use for communication. And by the way, I found that national semiconductor makes an LVDS transmitter that I think is compatable, so I'm gonna try to incorporate it into my first board (that way the LCD remains intact, so I can Ebay it if all else fails). I just need to figure out how to sync the dot clock with the Hsync pulse (non-existent datasheets are not helping) and this job will be done. Just out of curiosity, anyone know where I can find a datasheet on a Hitachi TX38D73VC1CAC (the last C just means its the third batch, so any letter here is acceptable) Hitachi isn't very good at returning emails.
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gotisos
Suspended permanently
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21. April 2005 @ 21:03 |
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I got money on a board if you can make this work!!!
something about a laptop lcd popping out of my dash makes me drool,
especially if I get to m0d something, and Im only using crap parts.
please PM me if you get this working!!!
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gotisos
Suspended permanently
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21. April 2005 @ 21:21 |
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I couldnt find the datasheet for your component, but I tried emailing hitachi to see if they could help.
if this works you should make a write up and submit it to hackaday.com
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DeanMan
Newbie
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22. April 2005 @ 09:17 |
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I have emailed Hitachi, and also Hitachi's American Distribution branch, never heard back from them. So unless you used something other than the "contact us" link, don't expect too much.
Its ok though, I found the datasheet for the LVDS receiver and I'm gonna pray that the signal is fed from the LVDS reciever to the LCD driver unaltered. If so, then I just need to make the monitor signal look like its the LVDS receiver's output. I guess its worth a shot.
As an update: I have about 6 different ADCs in shipment (all free samples). As soon as those arive, its off to the races. The only issue I still haven't worked out is how to get a train of 1024 dot clock pulses between each Hscync pulse (frequencies have to lock to one another). I'm trying to avoid using microcontrollers for the sake of anyone else who may want to try this. Anyways, we'll either know succes or failure real soon.
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bytedawg
Newbie
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10. May 2005 @ 07:21 |
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Thought I'd add my two cents to this forum since this is a project I also have ben working on for several years but at a snails pace since it is not a priority for me. As has been stated, LCD's are digital and most monitors are analog/RGB and the two are not compatible without a converter however if you can find a video adapter with a DVI connector, a lot of the new cards today do have them as well as some older ones, the project just requires collecting the lcd wiring diagram and mating the wires to the appropriate DVI connector, unless of course you have been an lcd repair tech for awhile. Convertors are another story and sometime a few years ago someone had posted a diagram with pictures on how to build them/one on the internet. They are also available in other forms from places like fry's electronics if you know what you are looking for, while the adapters from earth are very good they are expensive. Anyway if I get the time I'll search my systems and post info as well as pull out my home made convertors and provide info on them. Good luck all with your projects. Forgot to mention, I actually have made the project work with an old sharp 10" screen now I just need to get one of my 14" lcd's setup.
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ceteras
Newbie
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16. May 2005 @ 09:36 |
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Hi!
The simplest way to do it is by using a DVI receiver and a LVDS transmitter. You can find LVDS transmitters (I found one in a broken laptop) but with DVI it's harder. That because DVI includes Digital Rights Management tricks.
For example:
http://www.siliconimage.com/products/product.aspx?id=14
This Sil861 chip can receive DVI and send LVDS. You get the job done.
If you can buy a such chip. I couldn't. I don't have their e-mail no more, but they said that they cannot sell me a such chip because DRM.
I couldn't even find a datasheet for it.
So, forget about DVI! The only way is to fina a broken TFT monitor with it's electronics still working. Which is the way I could manage to display image from VGA to laptop LCD's.
Still, another way around would be as follows:
in some cases, the path from your pc to the TFT panel is as follows:
(true for VGA cards with external DVI transmitter)
GPU-digital video port-DVI transmitter-DVI receiver-monitor controller-LVDS emitter-LVDS receiver in TFT panel-LCD other guts-your eyes. ;)
if you're good at soldering 2 wires per milimeter, you can do this:
-unsolder LVDS receiver from flat panel
-solder 3x6 wires for data + 4 for controls=22 wires from your video adapter to the crippled panel. the path would look like this:
GPU-digital video port-LCD other guts-your eyes. ;)
You might need a surgeon friend to hlep you, or a lot of patience and time to do it.
This wouldnt work for higher resolutions than XGA and wires longer than 10cm/4-5inches. It could still be a good idea for a TFT flat panel sticked to your computer case side cover. I guess :P.
I haven't done it, but I have 2 panels at home, and I intend to give it a try once I get more data, and an appropiate VGA card.
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ceteras
Newbie
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16. May 2005 @ 09:51 |
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and here's another one:
if you search the net for ~"geforce mx" lvds~ on google you'll findout that every geforce chip has integrated LVDS transmitter, but that no VGA card makers actually route those pins out for us to use. And that's a big shame.
There are few industrial equipment manufaturers who make VGA boards with LVDS ports. The same google can help you find them. But these boards are very poor at 3D and I'm sure they are far from being cheap.
Another way to do it woul be by means of ADD or ADD2 cards for intel chipsets. Just type "lvds add" on my favourite memory replacement site (gugl :P). This link is most interesting:
www.kontronuk.com/pdf/ADD_LVDS.pdf
I couldn't find a supplier for a such board anyway, so if anything I have written here could hlep anyone make a progress, please let us know!
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Kreyon
Junior Member
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19. May 2005 @ 12:46 |
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Was wondering if there is any difference to try and use an LCD for a Monitor for DVD or TV signals in cars or whatever.
I am not looking to send a computer input to it, just simply a Composite Signal from a Cheap DVD player for the car using an old Laptop monitor. can this be done? if so, would it be easier than the discusion about sending Computer signal?
I understand that to send a Computer signal it might need more juice but if I send a simple composite signal would it be able to understand it? I really get tired of seeing these 5" to 7" monitors being sold for the car these days at $150 to $500 and all they are capable of is beiing a MONITOR (not a tuning device and no other functionality). I have a few old laptops with 14" monitors that I would like to use in the car now that the laptops dont work (or are so outdated) but I am not sure of what needs to be done to get the signal to the device.
the current monittor I am toying with is a 15" from a Sony Vaio laptop, it has a grey and black wire coming out of the right side, and a small connector with about 40 tiny wires going to it( they are split into groups of (4) red and black pairs, (8) blue and brown pairs, and some black wires and a few others. My Problem is that I dont know which is power and which are for input signal, I found that when taking apart the machine the (grey, Black) set was hooked to a small "daughter" board on the inside of the machine which I took out as well (just in case) My feeling is that this is the Video signal for the monitor (this laptop also had a TV\Video output(miniplug) but I am not sure.
if anyone has any ideas on this I would like to hear about them, PLEASE!!!! I have been trying to find info on this for a while but dont seem to get too far, I know this can be done because I have seen it and I know that it should be somewhat simple but I need help!
thanks
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ceteras
Newbie
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19. May 2005 @ 22:39 |
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The grey and black wires are for the backlite of the panel, not for TV signal. The 40 tiny wires are the data send to display. You should have read the thread before posting ;).
The composite signal is the same story as VGA output: it's analogical. And it's even more complicated to handle it's conversion to digital flat panels, because TV signal is interlaced, not Progressive scanning. interlaced means the picture is split in two, each odd horizontal line goes to the first half and the even to the other, and these two halves are sent one after the other. So it takes a special IC to do "deinterlacing", meaning memorising each pair of even and odd frames and restoring the actual picture to outputs, in the correct order of horizontal lines.
Believe me, it's not for DIY.
There are some chips that do conversion from VGA and TV(S-video) input to the LCD panels. Their pin counts are as high as 208, so no DIY again . Genesis is one of the makers.
I'm sorry to give such bad news.
I promise I'll be back with the good ones!
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Kreyon
Junior Member
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20. May 2005 @ 11:52 |
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Ceteras,
Thanks for the info, I did read the thread first but was getting confused by some of the terms. I just thought it would be cool if it could be done(easier), I will not give up hope though.
I suppose if I wait another year or 2 they propably will be cheap enough that I will wonder why I wanted to do it this way. and you would think that as much as sony wants for replacement screens there should be more of a use for them when the machine dies (sony will replace screens for $777.60 Flat rate, all other parts of the laptop can be replaced for $296.10 flat rate) anyway I Thank you for the response and I will keep watching the thread and see what happens, who knows maybe someday someone will actually see the benefit of making a small converter, and we can start to take apart the old laptops and reuse the screens instead of throwing them all away because the Motherboard died. I would gladly pay $50-$70 for an adapter of some kind that would let me use the 15" LCD for whatever I want, rather than spending $100-$299 for a small 5"-7" screen. Who's with me on this one?!? I have a soldering Gun and a steady hand if someone has plans to follow!! seems to me enough people are interested that we could make some $$$$$$
thanks Again.
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bytedawg
Newbie
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22. May 2005 @ 11:01 |
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I'm not sure why this is so confusing. Most of the posts have been relatively comprehensive and accurate with info regarding using laptop screens for desktop displays. I would disagree though that this project is not for the DIY. That is, if you have lots of time and/or money. The real issue is that not all laptop displays are created equal where a vga monitor is a vga monitor for the most part and a vga signal on a 15 pin connector will drive almost all vga dispalys the same as well as a 9 pin vga will operate most 15 pin vga signals with the appropriate inexpensive adapter. However, though the project is somewhat technical, hardware can be purchased to make the project as simple as connecting the cables together but this also depends on the LCD to be used. Just watch out for the high voltage ignition for the backlight but then the backlight is also something that can be bypassed and the display can be viewed somewhat normally.
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tuc
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24. May 2005 @ 13:10 |
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