Installing a Backlight kit (HiVision AIO) in a Game Boy Color
Channel: makho
Date: 23/11/2019

For those waiting for a 100% drop in GBC backlight kit, here's your opening. This kit requires absolutely zero permanent modification to your console and does not require any soldering or shell cutting. At all. Even for brightness control. 

I picked up one of those "AIO V2" kits for Game Boy Color. The cool thing about this kit in particular is that the kit is compatible with both the Game Boy Pocket and the NeoGeo Pocket Color as well. You just need to specify which ribbon cable you need (as all three consoles have different LCD connectors). No soldering is required for the install in the NGPC or GBC, but you will have to solder to install this kit in a Game Boy Pocket.

You might want some spacers to help position the LCD in the shell. You can reuse yours from Freckleshack (if you have one, of course) or print new ones: https://www.thingiverse.com/thing:3732645

Don't have a 3D printer? Check out my FR4 based spacers: https://youtu.be/glaM-D5HjBo

If both of those options are unavailable, the gap on the left (inside) should be 6.1mm and the gap on the right should be 3.6mm. You can probably DIY some spacers with cardboard or wood or even just do your best to position the LCD and secure it with double-sided tape. 

This is not a Freckleshack clone. There is a Freckleshack clone but this is not it. You can get this on taobao, aliexpress, ebay, Retromodding, or even Funnyplaying. I'd share a link to the particular kit I nabbed but the seller has taken it down. 

"Wow! That sounds awesome! But wait, there's got to be a catch, right?" you may find yourself saying. Well, yes, there is indeed a catch. Like the McWill kit, this kit runs the LCD at 60 FPS despite the GBC running at ~59.7 FPS. This means that every few MS the LCD needs to duplicate a frame to allow the GBC to catch up. This results in some noticeable judder, especially on any games that include smooth, constant movement, much like in any of the Pokemon titles. The McWill mod deals with this by introducing some occasional tearing, this kit straight up drops a frame or two to deal with the framerate mismatch. This framedropping occurs significantly more often on this kit than the tearing on the McWill kit. 

Warning! I have some examples of this issue in just a sec but once you see exactly what the issue is, you'll have a hard time not seeing it. If you are interested in this kit and generally don't notice framerate issues, it's probably best to not look at the slow motion footage. Examples are from my V1 kit in particular but since V2 did not resolve this issue in any way, they are still relevant. 

For example, this kit: https://gfycat.com/descriptivesarcasticcrocodileskink

vs the McWill kit on the same sequence: https://gfycat.com/hoarsebaggydarwinsfox

Freckleshack does not have this issue but at over twice the price (after shipping) and with how quick BennVenn's kits sell out, you might have a hard time getting your hands on one. 

This kit comes with several different options for brightness control. You can use the included sensor over the IR window, you can wire in your own sensor (what I did), or you can use the button pads to wire up brightness controls. You can wire them up to whatever buttons you want (my choices would have been select and down) but the operation is pretty much as expected. You wire up the "hold" button to enable brightness mode, and then the other button to toggle the levels. 

Here are the vias you can use (thanks bsparks!) instead of having to use the test pads on the front of the board: https://i.redd.it/af9szectfpu21.png

Make sure you double check the vias with a multimeter as the location may change between motherboard revisions. 

tl;dw: the kit is very easy to install but still has the frame dropping issues of the earlier revision. Battery life is worse than stock, but you should still get plenty of time out of your batteries.