Techwarelabs Community - use laptop screen on a pc??

Ok, here's the answer to your question. And no, before you ask, I haven't done it yet I only started 2 days ago. still need info on my MB to even stand a chance. Now then, as stated a couple years ago on this thread, nearly all older lcd panels have completely different pinouts/driver specs. Also as posted earlier each of the older MBs have the hardware driver built in which connects to the prosessor core through a standard data BUS built onto the MB.

This bus in pre-Pentium systems is probably ISA but may be PCI, in P1-P2 or so It's probably PCI but may be AGP, in most new systems it is AGP.

If your system uses the ISA achitecture your hopes of dual display are dashed unless you are able to code a custom driver to lie to windows that it is a PCI device, not sure bout dual display in linux but if it can be done there is probably an open source driver already out there for Multi displays using ISA. This assumes that your 'puter supports ISA as most no longer do. there are PCI riser cards however which bridge to ISA. All which I've ever seen have proprietary connectors though and we again hit the spec finding wall as the manufacturers usualy didn't bother to label them. with a bit of creative soldering however it can be done.

Once you find out the BUS type from the manufacturer you need to remove the display adaptor. If you have one which unplugs you're lucky otherwise like me you'll have to beg around for specs. Just tell the companies you contact that you are a student or they WILL be most unhelpful. It's not a lie as you are becoming educated ;) . after you have the requred information you have a few options. You could jot down a wiring diagram and make your own contoller card using the parts from the MB (I recommend this ONLY IF YOU KNOW WHAT YOU ARE DOING. if you trash anything or over heat the controller IC you will need another identical MB to start over with), or you could get out your hack saw and cut around the entire circuit which could then be wired to a riser card of the correct bus type. Simple riser cards range from free to ~$10 US at your local computer graveyard. Heck, most will also give you the junk laptop too, just to get rid of it. Junk, only in that it runs on a 40MHz 486 WINCHIP. Basicaly too old to sell in good faith. Mine even came with the original 'pleather' case.

now that you've sucsesfully modded your old display adaptor and have it plugged into your system it's a 'simple' matter of downloading and installing the driver. Drivers may or may not be available for your specific
OS however XP should be able to initialize it as standard vga adaptor at 16 bit color 640x480 res. Other simple tweaking of standard driver settings should be possable. If it's new/old enough linux and windows both should have correct or compatable drivers included with the base installation.

OK, so this project is not for nubes as a complete walkthrough would have to be made for every onboard adaptor that has ever been made which would turn into a realy huge project on WIKI or somesuch. offboard adaptors would be easier as there is some degree of standardization on a per-brand basis. Further reasearch could even allow merging part of the old controller to a better vid card which comes with it's own driver cd.

Ok that covers the old school displays now on to modern ones. This is a far sight easier. Most modern panel manufacturers have agreed upon a standard for panel controller signals and can be used on almost any device capable of driving an LCD. there are quite a few of them, all very much cheaper than a flat panel display. A simple google seach will unearth hundreds of them so I won't even bother to list any of them here. you must have the specs of your display to find out if it's compatable before you buy it or it won't come close to being worth it. once you have a compatable panel and display adaptor in mind try ebay to get a better price as usual. many of these adaptors are MINI-PCI and cheap. to use these you would simply buy a PCI to MINI-PCI riser for less than $10 US. Again, google to find these or print your own. OR try your local computer graveyard as they probably will simlpy give you one or sell dirt cheap. Old panel method will work too but this is easy to the point of being worth it. The only wiring absolutely required in the second method would be ensuring the correct pinout from the LCD.

As for the inverter to power the backlight use the parts from the old laptop or buy it. If the light is a cold cathode tube get that type inverter if EL use EL inverter. Easy way to tell the two types apart: if it's glass its a CC Tube If it's anything else it's EL (Tape, wire, rubber, plastic, etc.). Very rarely you will find LED arrays or light bulbs. If it has light bulbs replace with CC, EL or ultra bright LED as bulbs produce heat which will kill the LCD assuming that it even still works. If lighting is LED type no special wiring is needed, just DC power and a resistor. Value of the resistor will vary depending on the current draw, #of LEDs in array,type of array, and votage applied. Typically however LEDs use 35mA current for maximum brightness. Unless specs state otherwise never go above this or they'll die,melt,explode, etc. Generally during normal operation a LED will be 1.7V from Cathode to Annode. If you have a series array current is constand but voltage increases so to figure out voltage multiply the # of LEDs by 1.7 then subtract this voltage from the desired supply which must be greater than the calculated voltage of the LED array. If it's a parallel array the Voltage will be ~1.7V but they will take more current in the form of # of LEDs times .035A. You now have the voltage across the resistor and the current which must pass through it. To calculate the value of the required resistor ues the equation: R=V/I where R=falue of resistor in ohms V=Voltage across resistor and I=current in amps. In any case a .5Watt resistor of the correct value or higher as available will work without getting hot. Though I wouldn't recommend using greater than a 12V supply to be on the safe side.

To to this for free is, as I stated, simple. But requires a great deal of skill, time, energy, and patience. It just sounds more complex than it realy is. Will post more another time. also will try to give info on my MB if I can find it.