How To: Make a Case Screen (from a portable DVD player) - Overclock.net

BlackandBlue · 07-08-08

Introduction:

While cleaning out a closet at work, we found an old portable DVD player. It was a display model that got lost in the clutter, so they were just going to toss it. I figured I'd take it hope to see what I could do. I had seen a bunch of case mods with the PS1 portable screen, so I thought I would do something similar. I posted this a while back, but never had the time to make the tutorial.

Parts needed:

Screen from portable DVD player (I used an Audiovox VBP800)
wire (~18 guage)
solder/soldering iron
resistors (15k ohm, 12.5k ohm or potentiometer of similar value, 75 ohm)
4 diodes
spare 4-pin molex to plug into psu
s-video cable
Velcro to mount
3m electrical tape
duct tape (have you seen a mod without this?)
optional: on/off switch and shrink tube

Directions:

I started by taking the unit apart to see what we had inside. Most of the boards were for audio and the DVD drive itself. Turns out that the screen only needed one of the boards that were inside the case.

The molex plug on the daughterboard happened to be labeled for this particular model. The contacts were labeled with 9v (x2), ground, 'Y', 'C', and 'Bright' on the main board. There was another 2-pin plug on the side of the screen, and this is what actually had the 'Y' and 'Y-ground' wire. So in other words, there was a place for the 'Y' wire in the main harness, it just wasn't being occupied.

I started off by making sure I could power up the screen with the computer's psu. I ended up using 4 diodes in series to drop the voltage from 12v to 9v, since each creates a .7v drop (stripes away from the power source). I'm sure there may be other ways to get the 9v, but this worked for me. I used the supplied a/v cable to ensure I got a picture.

Next step after verifying success was to get rid of the bulk parts. I disconnected the daughterboard from the DVD drive, volume board, etc. I removed excess parts and tried out the slimmed down version.

I searched around online and found that Y and C corresponded to the s-video specification. After a little research, I was able to connect my screen to the s-video cable. I cut the end off a s-video cable to connect to the inputs on the daughterboard.

Pin 1- GND Ground (Y)
Pin 2- GND Ground (C)
Pin 3- Y Intensity (Luminance)
Pin 4- C Color (Chrominance)

I connected The 'Y' and 'Y-ground' to the corresponding wires from the screen to the cable. I connected the 'C' wire to the corresponding wire from the screen to the cable. There was no 'C-ground' on the screen, so that was left unconnected from the s-video cable. The end result was that the brightness was very high and the color was off. From testing, I found that the 12.5k ohm resistor took care of the brightness (when placed on the 'bright' wire and the 9v source) (use a potentiometer if you want it adjustable. One that has a few thousand resistance difference with added resistors to bring you up to the correct level, such as a 10k resistor and a 1k-3k pot in series) and the 15k ohm resistor lowered the saturation to a suitable level (this was placed on the 'C' wire, between the screen and the s-video connector). According to s-video specifications, you must terminate the connection with a 75 ohm resistor in order for the screen to be recognized automatically. I placed this resistor across the 'Y' and 'Y-ground' wires.

Close up of the resistors. I did not have the correct values, so I had to make them out of a few. Remember when in series add the values, when in parallel, 1 / R = 1 / R1 + 1 / R2 + 1 / R3... to get the value.

Now with everything working the way you want, its time to solder and clean up all your connections. I also covered the back of the board with duct tape so it would not short out. I used shrink tube to cover the wires and the 3m tape to cover the connections.

Finished product

Connection to video card and on/off toggle switch mounted. (if you have SLI, must be disabled) Installation of toggle switch will be inline with the +12v (or +9v), it will just interrupt the positive line.

Slapped some velcro on the back and top of the screen and some in the case to mount.
Enjoy!

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