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View topic - Help! McWill mod not working properly

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  • Joined: 03 Jun 2018
  • Posts: 2
  • Location: Racine, WI
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Help! McWill mod not working properly
Post Posted: Sun Jun 03, 2018 11:21 pm
Hey guys,

So I seem to be having a bit of a dilemma. I recently picked up two Game Gears at the Midwest Gaming Classic for about 30 bucks total. Both of which had screen issues, one was partly working, the other one was extremely distorted. The one I'm working on had an extremely distorted screen, so I decided I was going to do the McWill LCD mod to this one.

Well, I got everything cleaned up, wired up exactly to how the instructions had stated it should be laid out and wired up, put the batteries in and turned it on: the 2SB1301 Power regulator on the power supply board smoked. I quick turned it off, checked the power and ground, found that there was a direct short to ground somewhere. After testing, I found that when I had the wires hooked up for power on pin 1 of the brightness pot and ground on pin 3, it created a direct short to ground. So I unhooked it, tested it again, and had now 330 ohms from power to ground, which didn't make me feel all that better. So I tested it again, the screen came on, but the display was all sorts of fuzzy and the power died within a matter of seconds.

To make sure that everything was hooked up right, I checked all my solder connections to see if they were shorted to ground, none were. None were touching anything else on the old LCD ribbon. The only thing I haven't done is recap the boards. Which with the Power regulator smoked and dead, wouldn't do me any good anyway. My question is, has anyone else had any issues with this mod not cooperating properly, or is there something I'm missing? I've got a few pictures posted, with a couple wires removed to make sure that nothing else was wrong and shorted out. Any help would be super appreciated!
20180603_181434.jpg (3.71 MB)
Screen Side
20180603_181441.jpg (3.83 MB)
Cartridge Connector with wires soldered
20180603_181450.jpg (4.39 MB)
20180603_181458.jpg (3.55 MB)
Soldered screen wires
20180603_181522.jpg (3.27 MB)
Power supply PCB

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  • Joined: 14 Aug 2000
  • Posts: 480
  • Location: Adelaide, Australia
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Help! McWill mod not working properly
Post Posted: Mon Jun 04, 2018 1:35 pm
From the photos it looks like you've killed Q3 on the PSU PCB to the right of the MB3775.

Note, I haven't done a McWill Mod myself so I can't help you. This is just what I can see in the photos.
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  • Joined: 05 Jan 2006
  • Posts: 224
  • Location: USA
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Post Posted: Sat Jun 09, 2018 8:43 pm
I developed a replacement GG Power Board that is much safer than the original one and has more protections. I've installed some of the McWills and have a bunch of game gears on hand in case you want to send this one in for repairs. Drop me a message if you wanna talk about rates and stuff.

The real question on this one is whether or not you blew up the FPGA. Though I imagine it's probably all right as there is an LDO in between.

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