alfonsg00 wrote:

I took the lcd board from a working gameboy and plugged it into my faulty unit. And then it worked. So the problem seems to be in the lcd board?

Yes - It could be the white ribbon cable that connects the two boards, the brown ribbon cable under the LCD, or possibly a broken contrast wheel. You can try pouring a bit of rubbing alcohol into the contrast wheel and turning it rapidly to see if it fixes the issue, but it is most likely the ribbon cables.

Now i have tested the White ribbon, it's good. Tried push the 2 black ribbon cables and No change to the picture

Removed and cleaned the contrast wheel in alcohol, No change, maybe it could be a cap issue? Because if i have the console turned on for a longer period it does take longer for the static noise to go away when i turn it off.

alfonsg00 wrote:

I took the lcd board from a working gameboy and plugged it into my faulty unit. And then it worked. So the problem seems to be in the lcd board?

Yes - It could be the white ribbon cable that connects the two boards, the brown ribbon cable under the LCD, or possibly a broken contrast wheel. You can try pouring a bit of rubbing alcohol into the contrast wheel and turning it rapidly to see if it fixes the issue, but it is most likely the ribbon cables.

Hi, thx for the reply, i have tried to clean the contrast wheel with rubbing alcohol, but No difference, i messured the voltage from the contrast wheel and it changed values. Also like the thread starter the screen get the strange picture when i turn off with the static thing. Can you messure with a multimeter if for example the white ribbon cable is broken?

Orgia Mode wrote:

This is the power board:
https://gbhwdb.gekkio.fi/static/dmg/GM1 … d_back.jpg

Did you say the LCD "does" or doesn't" work on another gameboy.

I took the lcd board from a working gameboy and plugged it into my faulty unit. And then it worked. So the problem seems to be in the lcd board?

Yes - It could be the white ribbon cable that connects the two boards, the brown ribbon cable under the LCD, or possibly a broken contrast wheel. You can try pouring a bit of rubbing alcohol into the contrast wheel and turning it rapidly to see if it fixes the issue, but it is most likely the ribbon cables.

This is the power board:
https://gbhwdb.gekkio.fi/static/dmg/GM1 … d_back.jpg

Did you say the LCD "does" or doesn't" work on another gameboy.

I took the lcd board from a working gameboy and plugged it into my faulty unit. And then it worked. So the problem seems to be in the lcd board?

Did you say the LCD "does" or doesn't" work on another gameboy.

I recently encountered a DMG in this state, and I replaced the power regulator board from a different DMG and it fixed the issue.

Hi!

Where is the power regulator board located? That could not be my issue? I havet tried replacing the whole board with the screen attached from, with an working gameboy screen board and the screen works perfekt then...

I had a look at my LCD ribbon cable again and sure enough 2 pins towards the top had their connections broken. I re-soldered them and check the continuity but still no luck. I have a variety of boards with the same problem though and the others don't show signs of wear near the ribbon cable. I'll try and post some images later. Hopefully there's something I can do; it would be nice to know what to trouble shoot with this issue.

I have the same problem, screen black and slight change with contrast wheel, did you guys fix it? Tried everything, removed and reapplied new solder paste and the ground spots. Also went over every solder bit inside, remelted it. Did someone of you fix it? How do i know IF the LCD cable is bad?

While replacing caps is good practice, it shouldn't be the first step when troubleshooting, since the caps in DMGs are pretty good.

I've followed the advice in this thread thus far but it hasn't resolved my issue. I'll list what I've done:

LCD board modifications:
* Installed new capacitor kit (C1, C2, C3, C6, C7, C8, C9, C10)
* Replaced 100 ohm and 1k ohm resistors
* Replaced 47uF capacitor C4 (not part of the kit)
* Transplanted tested-working potentiometer
* Resoldered the grounding contacts

What's not replaced:
* Diode D1
* Capacitor C5
* DA1, DA2, DA3, DA4 (Rectifier diodes if my research is correct)

Way way back I bought a lot of 5 LCD boards that were supposedly dead off eBay. Only 1 was damaged beyond repair so I do have some spare parts I can salvage if that's of help.

edit:
applying pressure (brown ribbon), gently wiggling around (white ribbon) brings not change at all, not even slight hints.

To clarify, you put pressure on the soldered connections, underneath (not below) the LCD?

edit: I really need to read the thread before replying.

What did you reflow to get this working exactly?

Even though working, its rather faint and flickers. I resoldered the connections of the wheel, and freshened up a few other solder blobs that seemed dull, to no avail.
I might try a complete recap those days.
Thanks for the suggestions and I hope some day this info might help someone else

The rear side of the LCD Board. I replaced 3 caps (C1, C2, C3) with caps from a scrape board, as well as the contrast wheel, assuming it would help, but nothing changed. The screen shows the same behavior when C3 is not soldered in at all (I wanted to see a changed behavior if a cap is missing).
The Jumper J2 had some corrosion form this side of the board, close to the left hole, you can still see some. I cleaned it with vinegar essence as good
as I could.

edit:
applying pressure (brown ribbon), gently wiggling around (white ribbon) brings not change at all, not even slight hints.