spinach
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Hello everyone!

I have a problem with my modded gameboy and want to ask you guys, because i didn't found something useful at the internet.

I've modded my Gameboy DMG with a backlight, a bivert chip and a rca-prosound Mod.
Now everything works, but after a while (about twenty minutes) the display gets darker and darker
till it DMG completely shuts down. when i do power OFF and ON, the display  is still dark.
after waiting some hours and than turning the gameboy ON, the display is bright enough again
so i can play another twenty minutes till the same problem appears :-/

does anybody has an idea how i maybe could solve that problem?

(Its no problem for me to open up the gameboy again and do some soldering,
but i'm really not into the electronics).

catskull
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NUMBSKULL

Kinda sounds like the power regulator board might be overheating? I've never seen the screen getting darker because of it, but it's a possibility. What game are you playing when it happens? What kind of cartridge, official nintendo or some kind of flash cart?

Other idea might be simply some bad caps somewhere.

HoneyWizard
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Did you include a resistor on the positive end of your backlight? Mine was doing something similar until I added a 100 ohm resistor. It still overheats if I play table-heavy songs for an hour, but it's much better. Playing normal games, it isn't a problem.

egr
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Abandoned on Fire

Hey catskull that reminds me, how feasible would a new regulator board be to design? Seems like something that would have been done by now with all the power hungry mods that get added.

urbster1
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Naptown

i've done a mod to add a second power regulator to power the backlight actually - irony7 showed me this

the regulator used is this one: https://www.pololu.com/product/2119

(of course i just had my DMG open to where i could have taken pictures of this. i'll be modding another one soon and i'll snap a pic if anyone's interested.)

but, basically the board sits flush on the back board just to the right of the 4 points that connect to the power board. VIN connects to the top point, which is unregulated power from the batteries. GND connects to the point just underneath which is the ground. VOUT then connects to the power to the backlight.

edit: here is a poorly-made drawing, but gives a slightly better illustration. be sure to put a piece of vinyl tape in between the regulator and the copper as well (not shown) https://imgur.com/a/16YCu

Last edited by urbster1 (Jan 31, 2018 7:59 pm)

urbster1
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Naptown

a new power board replacement sure would be nice though, the 5v step regulators are easy to replace but the LCD voltage regulator might be a lil trickier

catskull
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NUMBSKULL

I looked into this a bit after little sound assembly, I'm 100% convinced the random crashes that happen at shows are because of the power regulator overheating. This is definitely something I've wanted to do for a while. urbster1 is right though, the 5v is easy, the -20v is the hard part. But then I remembered last night about a project I worked with uXe on a few years back and remembered he was driving the LCD. I looked it up, and sure enough he shared how. Here's the post describing it: https://community.arduboy.com/t/arduboy-classic/293/3

That method won't for more than a 1-off because the -20v regulator is obsolete now, but I spent about an hour last night scoping out replacement parts. I think it will be doable!

Worth pointing out too that in that post uXe claims that his solution results in better contrast on the LCD.

urbster1
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Naptown

first of all, wow!! yikes

second, call me lucky and knock on wood but i'm yet to have a DMG crash on me during a show. i think it's either power regulator overheating or else manhandling the game boy enough that the cart loses contact (or the batteries momentarily lose contact). my crashes at home are usually only when i accidentally drop the darn thing while it's on

Last edited by urbster1 (Mar 20, 2018 4:04 pm)

egr
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Abandoned on Fire

@catskull w00t!

spinach
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thanks a lot @ all! I'm  in this forum for maybe 1 month now and its great how (fast) people helping each other here! :-)
I had no time for doing gameboy stuff the last week, but i will try out your suggestions asap!