They are both DMG-CPU-06's with the same LCD board revision (I forget which - I think 06 as well?). Some of the noise comes from the 06's mainboard and, in fact, I tried mixing and matching at one point which helped some. A huge majority of the noise is on the LCD board though, even if I connect it to my good GameBoy's mainboard. My wild guess is that Q1 (that's a regulator right?) might be to blame.

I haven't looked at the CPUs though so I'll have to take a peak next time I have them open. Agreed, a new GB is probably a good option although it's a bit hit or miss on eBay and they sell for a bit higher prices locally for some reason.

If I were you I'd just go get a cheap original DMG and steal it's main board. The noise your talking about reminds me of any gb color's processor. You might just have a bad DMG... And they are so cheap it just seems like the easiest fix. Also is the main CPU a play it loud model with the blob for the cpu?

To add! With pretty much any backlit screen that requires you to cut out the left-side of the plastic guard, if you cut off too much and happen to hack off the plastic aligning pin/dowel as well, it can lead to the screen being mounted at a bit of an angle. If you cut the plastic and leave the aligning pin/dowel, it should center up pretty well.

Ah yeah I thought that might be it since I didn't think it was off-center before I removed the original screen cover so perhaps it was moved around while unsticking the glue or something? So I'm supposed to nudge the LCD screen itself within the plastic guard, or the whole thing?

I might just leave it alone until I'm brave enough to try an LED backlight mod on this thing. Since the mod does not appear to have been the cause of my audio problems on my other GB, it's probably a safe bet and would be a welcome addition for sure!

the screen looking off center is probably due to how the screen is seated in the white plastic guard surrounding it.  i've noticed this a lot...  there is enough wiggle room to push it to one side or another enough to notice.  next time you've got it opened, move the LCD a little bit and see if this helps.  a gentle nudge.

Hey nitro2k01! Sorry I never saw your update when I last posted and have been away for a week. I ended up just moving the pro-sound mod to my GameBoy that is much more quiet. The noise appears to have nothing to do with the backlight mod but something on the LCD board itself and was constant (Pro-Sound, headphone, power-save or not, always the same high pitched noise at the same volume) which is why I think replacing other components apart from the caps might help.

My good GameBoy sounds great with the only downsides being that it is not backlit and the LCD screen itself looks a bit off-center with the Chipmusic in Stereo cover for some reason. I used it all last week and it works like a champ so I'm going to call it good for now. I'd still like to see if I can fix the sound issues on my other GB at some point, but for now I have a functional solution at least.

I finally broke down and tried disconnecting the backlight LEDs, but it didn't appear to make a difference. I suppose the next thing to try is swapping out components other than capacitors (I've already replaced all of the electrolytics), such as Q1?

Ok, I'm entering science mode again. You will always get some noise from the headphone output. That's just to be expected, and why people prosound their boys in the first place. Newer versions of LSDj also don't have the power save option, but always go into a new auto mode. This mode should give only a minimal amount of the power save noise (basically interference from the CPU turning on and off) when LSDj is idle or playing a song. However, when moving the cursor, or changing screens etc, you may still hear some noise. This is normal. Here are some things to test.

On the headphone out, does the noise sound the same when you're not doing something and you're doing something? Or is there additional noise when you do something?
What happens if you create an empty chain with an empty phrase in it and press play. Any difference in noise?
What happens if you create a chain with a phrase with an pulse instrument with volume 08 (yes, silent) but otherwise unchanged settings in a new song, and press play? What's the difference in noise compared to nothing playing? Compared to the empty phrase?

I played around with it a bit more this evening. I removed the speaker since part of the annoyance was sound coming from it. This allowed me to compare the normal headphone out with Pro-Sound and I ended up discovering something odd.

When LSDJ is idle I cannot hear any noise from the Pro-Sound but I can hear it from the headphone out. If I start playing something on LSDJ, I can hear it from both outputs. So I'm not sure how the Pro-Sound is so quiet when nothing is playing when the headphone out isn't, but that they both exhibit the unwanted noise when I am playing something.

I used Kirby's Dreamland to test things as well and if I pause the game (no music), I can hear noise on both Pro-Sound and the headphone out.

I'm nowhere near solving the mystery but at least the noise isn't as bad as it was.

Wow well the problem instantly went away as soon as I blanked the screen in mGB. Sounds like awesome now. But since the LEDs are still active, that means there's less of a chance it's the LEDs, or is it?

As in, now that I know screen blanking works...it doesn't seem like there is much I can do about that?

EDIT: At least until I start using mGB Which still requires I finish up my ArduinoBoy (it's taking a break right now whilst I work on my MidiBox stuff)

I'm an idiot btw, in case you couldn't tell, to use a phrase popularized by raocow. Yeah, of course what I should've tried is to turn off the display. Of course that's what's happening during the time when the screen is blank.

nitro2k01: did you make a mode that turns the screen off?
m00dawg: you can also download and try the mGB rom from http://code.google.com/p/arduinoboy/dow … B1_3_0.zip
and hit Select + A to turn off the screen, I guess the noise would go away then. The high pitch wine reminds me of the GBC's screen wine issue.
You might not hear the wine after removing the prosound mod, but that may be just because the noise level is so high it will hide it.

The resistors shouldn't need to be changed on the leds, but the 6v from the batteries might be too many volts (6v max from there), though it probably will be fine.

I haven't yet had a chance to test this but my inkling is that it might be due to the backlight since the Pro-Sound mod is attached to the mainboard (and switching out the LCD boards alleviates the issue even with the mod). That would be a bummer though since I don't know what options I would have available to get power to the LEDs - using the battery terminals should give me clean power, although I wonder if I need a different resistance value since that is unregulated?

So I tried changing the contrast and the ROM. The contrast only helped very marginally. The ROM also didn't change the high pitched noise in any of the screen configurations that it cycles through. The patterned screen does create more noise than the others, but it sounds more like an addition to high pitched noise itself. I will try removing the Pro Sound mod today but will have to wait until this afternoon most likely.

I tried the ROM on my other GB as well and you can faintly hear a high pitched whine on what I think is the patterned screen. I can't tell because I have to put my ear right next to the speaker and can't see the screen Otherwise the normal noise from my good GB is basically constant (mostly some hiss and a faint buzz).

I am still banking on interference being the potential cause, though.

If the baclkight is connected through the regulated +5V and not directly to the battery (i.e. the usual points where the power LED was) you're putting a bigger load on the regulator. This may be contributing as well, maybe also depending on how good shape the electrolytic cap on that thing is.