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Modding PSOne LCD screen, Part one - Voltage Regulator

Discussion in 'Modding' started by r4tch3t, 31 Mar 2007.

  1. r4tch3t

    r4tch3t hmmmm....

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    Well Since I have had a PSone LCD screen sitting around waiting to be modded for about 6 months now, I guess I should start.

    First up is the Voltage Regulator.

    Since the screen uses 7.5 volts, Now there are several options available, first up is use the included adapter. This is not the most tidy method as it requires an external wall transformer and a cable trailing into the case.

    Second is to buy one of the Car adapters and use the 12V line in your PC, this is by far the easiest, but since when is easy fun or better?

    Third method is building your own Voltage regulator, this in my case was the only real option. I bought my screen in the UK so I can't plug the transformer in, and there is no were I know of that sells the car adapters.

    First things first, finding a way to drop 12 Volts down to 7.5. Now we can't do the 7V trick as although it would probably work with a slightly lower voltage, it creates an artificial ground at +5V. Now because this has other voltages and information coming in from the VGA signal it can create a short straight to ground, possibly damaging the LCD and you GFX card.

    So need to drop the voltage down to 7.5V, this can be done with a circuit including an IC called a Voltage regulator. A LM350 is the best one to use, but you can get away with using a LM317 or LM150.

    Enough words, let the pictures do the talking.
    The Circuit Diagram I will be using.
    [​IMG]
    This can be used for the 150, 317 and the 350

    All the bits.
    [​IMG]

    That regulator will get hot so, an old heatsink will do,
    [​IMG]

    Doesn't need to be that big, so mark were we need it cut,
    [​IMG]

    Down to size
    [​IMG]

    [​IMG]

    No in progress shots, but all soldered.
    [​IMG]

    That heats not going to go away by itself, so out with the trusty AS5
    [​IMG]

    Chunk of aluminum to sink that heat away.
    [​IMG]

    [​IMG]

    7.44V almost perfect.
    [​IMG]

    So the Regulators done.

    Will be busy learning to ride my new bike over the next week, but hope to get the LCD up and going soon. My X800 supports composite sinc :clap: so thats one less circuit needed.

    Comments? Yes the 12V line from the test PSU I was using was blue
     
    Last edited: 2 Apr 2007
  2. ElThomsono

    ElThomsono Well-Known Member

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    Nice work :)
     
  3. Hazchem

    Hazchem Member

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    it will be nice to see a FULL guide! GJ with the heatsink, overkill, but since when has overkill not been fun? I guess you could try watercooling the regulator as well...
     
  4. r4tch3t

    r4tch3t hmmmm....

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    Overkill? Never. Didn't want some puny sink that would cost me money, and I had a spare sink hanging round being a bum.
    Full guide will come, hence the part one in the title.
     
  5. gobygoby

    gobygoby New Member

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    nice job. Could you post a picture of the bottom of the board? Thanks!
     
  6. r4tch3t

    r4tch3t hmmmm....

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    Done, added picture :thumb:
     
  7. Hazchem

    Hazchem Member

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    well I guessed there will be a full guide, hence saying "it will be nice" as opposed to "would be nice".
     
  8. r4tch3t

    r4tch3t hmmmm....

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    Will be updating with the rest sometime tomorrow hopefully.

    [​IMG]
    Lost these so couldn't continue for a while.
     
  9. Warrior_Rocker

    Warrior_Rocker Holder of the sacred iron

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    Thank you for creating a guide and I hope the updates will continue. This may be something that should be either stickied, added to a sticky, or moved to the mod guides section. I also appreciate the fact that r4tch3tis building this from parts that can be easily found or sourced easily. I hope he keeps up the not storebought solution theme. I do have one question though. Are you going to hook up the monitor through RGB(vga) or through Composite? It would be nice to cover connecting it via RGB. Would be even cooler to see someone cover how to build the device you would need to get the PS1 monitor to accept normal vga output and not configured vga output through powerstrip.

    We get lot's of questions about PS1 monitors here in the forums and its nice to see someone cover the topic in a little more detail and with new revlevant information.
     
  10. r4tch3t

    r4tch3t hmmmm....

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    Not quite the big update I was intending, but anyways.

    [​IMG]
    The VGA cable, I bought this of TradeMe to use and found out that it only has 11 wires (Red Blue and Green are color and ground in one)
    Now this wouldn't be too much of a problem, except there are 15 pins on a VGA plug. Now 2 of these are not used, but that still leaves two unconnected.
    So I took out my trusty Multimeter and tested the pins to the wires. And here comes the downside, pins 9 and 12 were missing. For the mod you need pins 1, 2, 3, 6, 9 and 13. Pin 9 is +5V and lets the GFX card to recognize that a display is connected and to tell the PSOne LCD to turn on.

    So I connected it all up without pin 9 and wow and behold, nothing. So I hotwired the LCD with a little 5V action from the same connector as the regulator. The screen turned on. Yea.

    [​IMG]
    But nothing came up. Got into Windows and only one display was recognized, my main screen. No PSOne LCD.

    So I thought, well since pin 15 is connected, I will try tying that to ground. Turned the computer back on, had some green come on to the screen all messed up like, so success just need to tweek. (The ASUS logo on startup is green) But then I got to windows, and the screen again is not recognized.

    At this point I was just like well I guess I just wont use the cable, make me own.

    [​IMG]
    So used the one on the right.

    [​IMG]
    Wired the cable to the circuit board.

    [​IMG]
    And the other end to the connector, with a little hot glue to keep everything in place.

    Plugged everything into place, and pushed power, a blue spark and computer shutdown. AAAAHHHHH!!!!!!!!!!!!!!!

    Thought I killed it, unplugged the regulator and computer would not switch on. Tried switching the PSU on and off again... Nothing.
    About a minute later tried again and purred into life once more. The relief.

    Booted into windows, then shutdown. Plugged the regulator in again, with the offending piece of metal causing the short out of the way. Power up.

    [​IMG]
    Screen turns on without hotwiring.

    But still not recognized in windows.

    So sorry for the inconclusive update, but hopefully will have it up and running tomorrow.

    btw I am using VGA to power it.

    I would build a circuit to negate the need for Powerstrip, but the only circuit I found used parts I could not source here.
     
  11. mobius9

    mobius9 Member

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    do you still have the wall plug for the LCD? At least you could test that out to make sure, or try an adapter for the mini-rca in to double check its still working fine?
     
  12. ezland00

    ezland00 New Member

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  13. blaffer4x4

    blaffer4x4 New Member

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    little Q:
    is it possible to run the screen on 7V instead of 7.5v?
    if so, you can connect the positive lead on the 12v line and the negative lead to the 5v, resulting in 7v...
     
  14. dragon2309

    dragon2309 techie

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    I think this has been almost ruled out completely iirc, doesnt it create an atrificial ground at 5v, which shorts something else out, im sketchy on the details but i dont think it works as required
     
  15. capnPedro

    capnPedro Hacker. Maker. Engineer.

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    So, no.
     
  16. r4tch3t

    r4tch3t hmmmm....

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    It would probably run at 7V, but you cannot use the 7V trick as the LCD uses 5V through the VGA plug to sense when the screen should be on, there are also ground wires for the VGA plug. This would create a short directly from 5V to ground, not something you would want going through your LCD screen. Easiest way if you don't want a regulator would be some power diodes to drop the voltage to 7.2V.
     
  17. Warrior_Rocker

    Warrior_Rocker Holder of the sacred iron

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    The PS1 monitor also tends to be very tempermental when it comes to the voltage you input. The board really expects you to input something very close to 7.5v Stuff higher and the image starts to wash out or go white, stuff lower and you will notice the image destablize or the backlight flicker until it cuts off completely. Learned this fairly quickly when building my portable n64.
     
  18. Napalm Candy

    Napalm Candy New Member

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    You can to detect your monitor plugging another monitor that you had, it will detect normally by windows, and then switch for the PS1 LCD, now you can use powerstrip. But the best solution is connecting the PIN 9, it is DCC +5v

    Problems, I don't know if you know about C-Sync compatibility with new VGA cards. I has make this tutorial http://starfox.ucc.asn.au/carcomp/serio_lcd.htm with the C-Sync circuit. [​IMG]

    And it continued with the same images
    [​IMG]
    [​IMG]

    I don't know if it is normal, but i cant to get any image, only blue lines moving around the screen.

    Anyone can to help me? Thanks :)

    PD: Sorry my english
     
    Last edited: 27 May 2008
  19. modgodtanvir

    modgodtanvir Prepare - for Mortal Bumbat!

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    I didn't have any problems when I tried it... I just used a 12V DC rechargeable battery pack with the car adapter...
     
  20. HowY

    HowY New Member

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    If'in I could ever finish sweatin' up mine...

    Google DCC Prom 24LC21

    This will have the display "seen" as a valid display device
    and an easy patch into the system for a "true" vga display

    I used the 74LS86 for the sync combiner and like you a 317t
    for power - (Used a 220/1000 resistor combo 'tho) even tied
    in a QT touch sensor to power up the whole deal.

    Had to re-do the circuit to fit the area I'm installing it in
    and was hoping to get it together over the winter but
    lyfe stepps in....

    The DCC prom does need to be programmed but was
    a simple matter with the little display app mentioned
    in all the write up's (senior moment)

    Cant wait to see the write up! :thumb:
     

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