Ah yes, It could be from the other ports... Doubt it's from the long wires, because I mounted it right on top of the pcb. wires aren't even a centimeter...

Might try and ground the ports on my DMG, to hear if it makes any difference...

Hmm, as a side note to this conversation I just got my backlight and LSDJ today, and it was supposed to be inverted but I m not sure that it is... when turned on the Nintendo logo is black... and I can never get the contrast quite right, when most of the screen looks normal the upper corner is barely visible but when I adjust it to show the corner the colors do invert but I can't see the rest of the screen

I am using Kitsch's LED x3 Green (supposedly inverted)

Inverted is basically what is says.. inverted..
the black pixels are now white, and the white pixels are black. This is because the polarised sheet that is placed behind the screen is turned 90 degrees.

the reason people use this, is because it also turns the spacings between the pixels black, thus creating a bigger contrast in the screen. The problem with the contrast is indeed a bit anoying sometimes, and varies from colour to colour.. Make sure your batteries are full...
So you should get an inverted picture, if you get a normal picture, or half a picture, change the batteries, and adjust the contrast...

If you still have trouble getting your picture right, you might want to try and untighten the screws in your gameboy just a little bit (pcb or case) as the backlight takes up some room, the screen can sometimes be squashed causing the pixels to fade (Like what happend when you press your finger on your calculator screen)

SO I made sure my batteries were full and then messed around a bit, when the contrast is at an exact half it does look inverted but is very very hard to see, when any higher (as in turning the contrast dial away from yourself) it becomes impossible to see, the only thing visible is the word "song" in LSDJ and when cranked the whole screen becomes whiteish.

When the contrast is darker than half (turning the dial towards yourself) it then becomes normally polarized and is quite view-able except for the word "song" up in the top left corner in LSDJ, and when cranked  all the way is black.

I tried tightening and loosening screws to no avail, and looks the same way when the front PCB is dismounted, I have no clue what exactly is going on.

My DMG-01 had the same loud hum on the pulse channels like the OP talks about (disappears after a K[ill note] command is played). Removed the bivert chip (didn't try to ground the unused pins as suggested though), and it's all good. So, thank you thread. smile