Gameboy low contrast before/after backlight. Capacitors

I've recently modded my DMG Gameboy to add a biverted backlight.
Before modding it, I noticed a lack of contrast (I had no other DMG to compare, but I remember it to be better) and, after the mod, image is not very bad but I still notice a lack of contrast.

I thought about changing the capactitors to see if that improves the image.
I've seen some vendors that sell a pack of all the capacitors.
My question is: do you use to change all the capacitors at once or should I check them before (with the multimeter?) to see if I don't need to change them all?



Thanks.

 

I've finally bought a pack with all the capacitors. It will probably arrive in 1-2 weeks. I will report the results then.

 

Oh I just realized by comparing the image to an emulator that some of the colors are inverted (and I though I had followed the instructions...)

I've already received the capacitors so I will try fixing both problems.

 

Good luck with the cap change. Hope it fixes the contrast issue. Would you mind linking a guide on how that light mod is done, please?

 

Thank you. I will continue with this on Monday. I was following two guides, one that was linked in the product site and one that came printed on paper with the backlight. Maybe that's why I have screwed up the biversion. I will compare them to see where I made the mistake and I will upload the right guide then.

 

The low contrast appearance would be if you backlit the DMG without installing a bivert mod.
It's difficult to explain how it looks, but it is less dark than a stock screen to be certain. I don't do any of my DMG mods without incorporating a bivert mod at this point.
I'm wondering, which mod kit are you using? (If that's within the site rules to talk about, of course.)

As for cap kits, I tend to replace everything at once, just to save time, as I would constantly be testing the system to make sure each cap is 'okay' - which would double or triple the install time for me. Most likely, it won't fix a low contrast issue, but more likely help with cleaning up audio issues and keep the system stable and working for the next decade.

An emulator may be all right for playing games, but I personally wouldn't use it as a reference on a bivert mod. Some of the sprite rendering may or may not be accurate.

Had another thought - I had a Gameboy that had the problem yours has - low contrast - Now I just have to remember what caused it / how I resolved the problem. I believe it ended up being a problem with the ribbon cable, but don't quote me on that.

 

Before the mod the screen had also some contrast problems so I will see if I have some luck with the capacitors.

What the emulator is telling me here is that some colors are wrong: dark is OK, but Wario's face on the wall and background colors are inverted. Until I checked the emulator I thought that something was wrong but I wasn't sure. I'm out of home so I can't check right now where I did the mistake.

The mod kit including bivert is from backlight4you. Very nice kit as you don't need to cut the LCD frame. In the website they link to a forum thread with screenshots as a reference, but the kit comes also with some instructions. I want to check if there is any difference.

 

Currently things are worse than before
Caps replacement was OK and contrast improved, but I had the colors problem I described above.

I checked the bivert connections and one of the paths I had to cut wasn't properly cut, so there was a short between pins 3-4 of the bivert chip.
I checked all the connections but currently I only have two colors. Taking the previous screenshot as a reference, I can't see the Wario's face on the wall (sorry as the screnshot is from another place).

 

You do realize that the bivert chip is designed to invert the colours, right? perhaps you put the polarized layer in wrong? but now, it looks like your missing 2 channels of grey? Check your connections again.

 

When applying the bivert mod, the polarizer should show a dark screen when the Gameboy is turned off. That's the case here.
Yeah I'm missing two color channels. I may try removing the bivert chip and starting again.

One problem for me is that the main support forum for this mod is in German only:
forum link

 

Is this the chip you've installed? Appears to be smd-sized 7404 on a custom board with wires...
http://www.backlight4you.com/LED-Ba...PCB-for-the-Game-Boy-LED-Backlight::1064.html

Maybe cross referencing another wiring diagram might help you narrow down which pair isn't connected correctly?
http://www.mmmonkey.co.uk/gameboy-dmg-01-screen-invert/

 

Well I've finally managed to solve the bivert issues. I have a very cheap multimeter so it was a bit difficult for me to test the traces. Again there was a problem with some traces but now the colors are OK.

Capacitors made the contrast to improve, although theare are still some dark zones in two corners (the LCD ribbon could be the cause).

I'm leaving here the information and guides I've used, please make a better use of them than me. This is my first mod so I'm sure the next will be better.

Capacitors diagrams

 

The dark corners suggests that the screen and the light panel stuff isn't straight/flush with eachother. Might be worth reseating the screen and the light stuff.