Saturday, March 24, 2012

Kitsch-Bent electroluminescent gameboy backlight

The mighty kitsch-bent sent me an as yet unreleased electro luminescent gameboy backlight to try out. This was partly a successful experiment in shipping them longer distances (it arrived perfectly safe and sound), but also a favor - I've been waiting for these things for a very long time.

I've also been waiting for quite awhile to get my hands on a blue "play it loud" gameboy, which are rare in the US. Behold:

I figured what better way to celebrate than to install my brand new EL backlight in this much awaited blue gameboy.

For those unfamiliar with backlighting gameboys, you should know that the most difficult part of the process has not changed, and never will change - the polarizing sheet adhered to the back of the dot matrix screen must be scraped off so that the screen itself is perfectly clear. This is a somewhat difficult skill which takes practice. The real danger here is damaging the two thin ribbon cables that control the screen itself. I have heard of issues with the screen cracking, but I've applied quite a bit of force and never had that problem, so I'm afraid I can't speak to that.

What is often a hassle is the adhesive not coming off clean. That happened in this case, and the solution is usually rubbing alcohol and a soft cloth. In addition, I re-clean my screens repeatedly with a glasses cleaning cloth to make sure nothing rests on the screen that might scratch it. Anyway, you can see this one worked out fine.

Now let's open up the EL kit.

What you're seeing here is actually the back of the EL panel - the front is pink. The two metal contacts are what kitsch was worried about in the first place - he was concerned that they may detach, but they arrived securely fastened. The two white pads are salvaged from the original polarizing sheet, by Justinthursday's suggestion. The issue is that unlike traditional backlights, the EL panel is nearly as thin as the original polarizer, so it shoudl require the padding to keep the screen from rattling around. This wound up not working so well for me, but we'll get to that later.

Here is the panel fully installed. I should have taken more photos, but I found that I needed to cut away very little of the plastic frame surrounding the screen in order to fit the cables. It was a very comfortable fit.

There is a capacitor just beneath the screen which can be bent out of the way to make way for the two pin power connector to squeeze through. Pulling the cable up to the top of that hole and pushing the cap back into place makes for a comfortable fit.

Now that the front half is done, it's time to address the power inverter and the back half. First thing's first:

Looks like the battery contacts in this little guy have seen better days. The spring on the upper contact has disconnected entirely, and was actually hanging out near the speaker magnet. Typically I make an effort to clean these things, since there is a finite supply. I'll get around to it, but I've got a sleeping baby upstairs, so I'll just pull from a donor.

Much better.

This little heat-shrink-wrapped guy is the power inverter, wired up pulling power from the regulated 5V feed to the cartridge (and ground straight to the battery terminal). The inverter comes with a black and white cable pair for DC voltage input; typically black is used as ground and white as positive, but in this case the plug fits in either way at the inverter. The two input pins are different lengths, and the shorter pin is intended as ground, which is the opposite of the normal logic - typically connectors are designed to connect ground first as you insert them, to help avoid an unexpected shock when something is mis-wired. It's a minor oversight, considering that the amperage on this side of the inverter is negligible, and you're unlikely to be plugging this in while it's powered anyway.

The other side of the inverter has two identical pins to carry AC voltage out. If the inverter is powered without these pins attached to the cable hanging off the EL panel, there is a theoretical risk of burning out the regulator on the board. Kitsch says he's tried pretty hard, and failed to burn it out. I'm willing to believe him! Considering that there is a risk of shock from the more lively side of the regulator, it's probably best to keep it hooked up anyway.

All assembled. I'm really happy with how it looks, and I'm extremely happy with how not gawdawful bright it is - I've always felt that the LED backlights were unnaturally glaring in a dark setting, and I've always preferred the brightness level of a frontlit gameboy color, or the SP or DS. LED backlights have gotten brighter and brighter only as an attempt to even out the light by adding more LEDs - and while it's possible to dim them by changing resistor values, this also results in a less even light. The EL backlight is much more in my preferred territory in this regard.

There's been much question of noise added by running the EL backlight. The inverter definitely adds some noise to the internal speaker and the headphone output. In fact, when I tested the game boy with an AC adapter (which I usually do initially), there was a ridiculously loud (and sortof awesome) noise coming from the speaker. Batteries are much better, but there is a distinct hum, even with the volume turned down.

edit: what I described as a "hum" is really more of a high pitched whine, presumably at whatever frequency the AC runs at. It's honestly quite irritating for making music. That being said, I've discovered that the speaker in this gameboy is completely shot anyway, so while I'll probably remove it, I will test it out with an alternate known working speaker first, just in case.

re-edit: Kitch clarified a couple things for me, and you can expect an update to this post with the changes I'll be making to this install. In the meantime, I should mention that the place I took 5v from is not the ideal, and a lot of the noise problems are apparently alleviated by taking power directly from the power supply PCB.

What to do? Removing the internal speaker comes to mind - this offers some extra modding room as well. Additionally, "prosound" modding the gameboy is a necessity, as an output that bypasses the headphone amp should bypass the noise. I believe Justin has already confirmed this, and I'll be trying it with an ASM Retro panel mount pro sound within the next few days.

The other issue is that of the pressure points on either side of the screen. They are obviously caused by the white spacers on the back of the EL panel. Unfortunately, I'm upstairs with the baby and my tri-wing is downstairs in the basement, so I won't know until tomorrow or so whether removing the pads or loosening screws is the solution.

All in all, a great looking product, and an exciting step forward for the gameboy. I'm not entirely sure about recording with this guy until I get the prosound line in, and unfortunately I can't see using it as a home composition tool because of the noise. I'd need to disconnect the speaker to not be annoyed by it, and I do often work with the speaker  to lay out the basics of songs.

As a stage unit however, it will be fantastic - it's a much more comfortable light level, and results in a much easier to read screen. This is perhaps not so necessary for an act like The Glowing Stars where I'm taking only quick glances at my gameboys, but in an act like Matthew Joseph Payne where I'm doing more and more live mode stuff, I could get very comfortable with this. I'm excited to play with it more! Thanks again to kitsch for this opportunity!

1 comment:

Ultraaw Firefox said...

Recently,I got some pcs of the LED Front light for my game boys series and changed the backlight into a front light, it was a great.

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Hope this will helpful to you. Antony