Monday, May 11, 2009

Game Gear LED Backlight Mod





The following is a guide to a recently completed LED backlight mod I made on my blue Game Gear. Why do this? The standard Game Gear gets only 2-3 hours of battery life on 6 AAs. This is not good, and is largely due to the flourescent tube which illuminates the screen. With the LEDs you can get around 8 hours of battery life! Be aware of two things: the LEDs are a focal light source, and therefore will most likely have slight hot-spots nearest to the bulbs (see image). Secondly, I have found the screen is generally dimmer with two bulbs. The bulbs themselves are plenty bright and capable of washing the screen out if you turn the brightness up, but because the light is not completely uniform the screen is dimmer farther from the bulbs. Feel free to play around with more bulbs or different configurations - just adjust the resistor you use accordingly.

Please note that the mainboard depicted is not the original in the system - I replaced it with one from one of the Majesco re-releases of the Game Gear (better screen and audio). The Majesco boards have one primary ASIC controller chips, as opposed to the two on the original systems. If you have one of the original Game Gears, don't sweat it. This mod applies to either model.

I would also like to note that I did not develop this mod myself. A poster with the username of Tibia at the Benheck Forum was the brains behind this. She has also posted a guide, with much crisper images and her own instructions. The resistor I used in my mod is more conservative to ensure the LEDs don't burn out. The LEDs I used are also larger. Check her work out as well, and between the the two guides you should have more than enough info.

As Tibia also notes, you could potentially damage your Game Gear doing this. If you do it right, you shouldn't, but do this at your own risk!

You will need the following supplies for this modification (I've posted links to buy the less common parts):
  1. Soldering Iron
  2. Solder
  3. Screw drivers (philips, game bit)
  4. Pliers
  5. Hot Glue Gun or Epoxy
  6. Electrical Tape
  7. Wire cutters
  8. Wire
  9. Two 3.3V 5mm white LEDs

  10. 39 ohm 1/4 watt resistor
  11. Smaller sized heat-shrink
Step 1) Open up your Game Gear. This is mostly straightforward except for the security screw at the top center. You need a gamebit driver to remove this screw, or you can try to make your own tool for it (http://forums.benheck.com/viewtopic.php?f=3&t=5001). Don't try to simply snap it, you can crack your screen that way. I've done it.

















Here's the inside of the famous Game Gear. See those blurry red Xs? Those are the areas of interest. There are 10. The 4 components in the top left are dedicated to powering the CFL tube which currently lights the system. We will be removing them. We will also be removing the tube (obviously) and its resistors, marked by the 6 Xs around the reflector in the center of the system. Closeups are below.

Step 2) Remove all the screws mounting the mainboard to the case. The small screws passing through the white plastic right around the screen also hold the LCD to the mainboard. You should remove them to get the screen out of the way, but be careful when you do so it doesn't flop away and hit something or pull on the ribbon cable too hard.

When the screen is removed as far from the blast zone as the ribbon cable will allow, remove the reflector plate from the around the CFL tube. Now you can have some fun!

Step 3) Begin to desolder all the components marked above with the red Xs. Use the pliers to gently pull on the component while you melt the solder with the iron from the other side of the board. Some components will come off easily, like the CFL tube and the resistors. The large square transformer, however, might be difficult. Try to get the contacts on one side loose then work on the other. Do not throw out the rubber CFL tube endcaps. You will be mounting your LEDs in them.



















Here's a shot of the side where all those components used to be. The Xs denote these locations. Take note of the light green circles I marked on the board.
  • The two green marks within the white circle need to be connected to each other. Solder a bit of wire between the two contacts to resolve this.
  • The green mark by itself on the left of the white square on which the transformer sat is a ground point. This is where your LEDs will be grounded.
  • The green mark in the center of the five contacts at the bottom of the white square is the current source. It is 5 Volts, for those interested. The 39 ohm resistor will be connected to this point.


















Here's a shot of the other side of the board. Not much needed to happen here, just the removal of the CFL tube and its resistor. Those spots are again marked with the Xs.

Step 4) We now need to prepare the LEDs. I think it helps to sand the LEDs so that they have a milky-white appearance. This might help diffuse the light from the bulbs so they have less of a brightspot. Compare the one on the left to the sanded one on the right:




















Now clip the wires of the LEDs relatively short, and solder your wires to them. Make sure the wires have about 5" length to them to allow for mistakes. Take note of which wire is attached to the positive and negative sides of each LED to avoid mistakes later. Use heatshrink to insulate the bare wire and solder. Like so:



















Now feed the wires through the rubber CFL end-caps. Situate the LEDs so that the bulbs are submerged into the rubber caps (sinking them so the tip is flush with the opening of the end-cap has a better effect than the half-way position I've depicted here). Get them as nice and centered as you can, and fix them in place with epoxy to ensure your backlighting doesn't change with the movement of the car. It should look something like this:


















Once the LEDs are fixed firmly in place, glue the rubber caps to the sides of the reflector plate. They won't stay in place otherwise. It should look like this:



















Finally, connect the LEDs to each other in parallel. This means the positive wires from both LEDs are soldered together, and the negative wires from both LEDs are soldered together. From the unions of the positive and negative wires run a single wire to connect to the ground and power source on the board. The voltage source is 5v; there are numerous resistor calculators online for you to consider when trying to pair the LEDs you bought with appropriate resistance (in my case 25mah 3.3v wired in parallel: Try this calculator). I recommend trimming the LED wires on the side near the ground and power short to avoid excess cable in the case. Insulate the junctions where the positives merge into one and the negatives merge into one using heat-shrink so it looks like so:















Step 5) Now it is time to finish the job. Solder the resistor to the center of the row of five contacts identified above. Clip its ends short to keep a low profile on the circuit board. Position the reflector with its LEDs back to the mainboard, reposition the LCD screen, and use the screws to fix the two together on the board again. Solder the LED negative to the other end of the resistor. Now your LEDs have power. Solder the positive LED wire to the ground point on the board. Now the circuit is complete. It should look like this (only less blurry), indicated by the green lines:






















Finally, we need to make sure the wires don't get in the way of anything. Use electrical tape to affix them to the side of the reflector, like so:




















Your mod is complete. Put the Game Gear back together, pop in some batteries and enjoy the improved energy efficiency!

















**EDIT** I have since pursued modifications to improve the dispersion of the backlighting (reduce the hot-spots and allow for brightness to be raised without washing the image out as much). So far, I've had LITTLE SUCCESS.
But stay tuned, or offer up any suggestions! Also, if anyone has images of an improvement on this approach, feel free to share and I'll put your work up. There seems to be a lot of interest in this modification.

**EDIT #2**
I have since tried an opaque white straw as a diffuser (POSTED HERE). But the results were unsatisfactory.

23 comments:

  1. I've done almost exactly the same thing to my Atari LYNX. I found one way to improve light scattering is to find a piece of milky plastic tube and place the LEDs in each end making a psudo-flouro tube.

    I used a 5mm round milky white drinking straw.

    My Lynx with 6x 2650mAh cells and LED backlight will operate for around 7-9 hours!

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  2. Thanks. I started this but now I know where to get the 5 volts. Too bad I just burnt out my last led

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  3. Can you modify my gamegear if i send it to you.

    How much would you charge.

    James
    my email address is ssnjimb@aol.com

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  4. Thanks for the amazing post. It is nice to know that some can improve something. I used to have a gamegear but I was annoyed because I could play it longer periods of times. Maybe I would search for a used Gamegear on Viagra Online to see if I can finish a lot of amazing games that I didn't

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  5. Thanks everyone! I'd probably not be comfortable modifying someone else's game gear for them as there's a certain amount of risk of damaging the system involved (and that would be a shame). Feel free to ask questions, though, and check out Tibia's thread on this I linked above.

    It's a bit of work, and the end result from my approach isn't perfect. But it's certainly an improvement on battery life while maintaining playability.

    Wim's suggestion at the top seems like a great idea, and is the primary thing my mod was lacking - a better means of dispersing the light.

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  6. It is nice to know that some can improve something. I used to have a gamegear but I was annoyed because I could play it longer periods of times.

    led mini lights

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  7. I tried the mod, and it turns on for a second then shuts off. Do you have any idea of what i might have done wrong? This is such a great mod.

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  9. Grey, this can be a capacitor fault in your motherboard or a power board faulty, then you need to replace all capacitors. If you already made it, just change the power board from another system. Regards. Alan - Brazil.

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  10. I got it working. Just worked with the resistor. I think I didn't have a good connection. Very nice. Thanks.

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  11. wow such a nice game you can create by own great work i really appreciate that thank you for sharing...






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  12. I'm in the middle of fixing up a GG at the mo and it had a blown CFL, so I figured I'd go with LEDs .
    It occurred to me though that you could use the CFL tube as a light defuser, so I've sawn the ends of the tube and intend to mount an LED in each end (remember that CFL tubes contain elemental mercury which vaporises when the vacuum of the tube is broken, don't go getting dead).

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    Replies
    1. Excellent yet risky idea, now you're thinking!!! what's simpler than re using some of the old part!? now the question is just how evenly can we evenly distribute the light and is the old tube good enough? is it better than a straw?

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  13. Thanks All!

    I think the CFL mod might yield better results than a straw if the reflectivity of the glass allows the light to bounce around more within the tube before escaping. Could yield a more even light profile. But risky - whereas the straw is pretty much harmless to play around with.

    Keep the good ideas coming! I think the popularity of this post highlights the fact that there are still active retro-gamers out there looking to enjoy and improve upon their old hardware

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  14. Im going to attempt this mod but add 2 more LEDs and do all the caps, I bought everything just havent started yet, any words of wisdom before I start?

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    1. Good idea - if you have preferable results, feel free to share them. I'd happily post your pics and outcome on here (crediting you of course)

      Words of wisdom - I'm probably a bit late, but the main thing I guess is be gentle with the soldering iron as the contacts on the PCB are easily scorched. Also, replace and bad capacitors while you are in there!

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  17. wow such a nice equipment keep blogging...


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  18. First of all, thank you for this awesome tutorial!

    I'd like to add my own two cents. I followed your tutorial, but instead of two LEDs, I used one of these http://www.adafruit.com/products/1621

    I had to shorten it by approximately 1 cm for it to fit inside the GG. It's easy to do since it's made from plastic. Also it takes a bit of trial and error to find the correct spot where to put it inside the GG to get an evenly lit screen. But it does work quite nicely.

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    Replies
    1. Hey, that's awesome! Was the screen bright and did it have good color with that light? That thing is cheap and I could imagine being a much preferred solution if the answer is yes.

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    2. My first try with only one of these wasn't so amazing. I had better results with two stacked on top of each other. There's some white plastic film on both sides of the backlight. So you have to remove it on the faces where the backlights touch.

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