I got it going.
It seems I was using the GB cable layout instead of the CGB layout as when I use the GB connection on my cable the keyboard doesn't receive any power.

The connections (from looking at the contacts underneath the PCB) are:

Blank | Blank | Clock
Data  | Power| Ground
|                              |
| LINK PORT HERE |

Video here
(Bad quality)

I just discovered that the cable has 7 lines, one is the ground for the cable.
It should work, but it doesn't.
I'm gonna switch the cables around a little.

Actually 4 lines means it certainly has no 5V line.
The ones on a standard 2 way link cable are data in, data out, clock and ground.

Sweet Dude!!!! I have some ideas to spice it up, after it's made into a web page I think I'm going to find a way to organize and keep track of Chains and phrases too.... (ever make a bunch of chains/phrases, and forget where you put it??? Yeah I want to make it easier to keep track of that stuff... lol)

Thanks and I'm still working on your HTML patchbook thingy. Dreamweaver worked well, I just gotta get the spacing right.

Oh right, thanks, I'll have a play around with it.

No, it doesn't (I think), I'm going to post a full tutorial when I've got it working.
It's pretty much the same, just soldering to a different place.

Well, they have four lines and I have a little power, so I think they do, but if anyone has confirmation that they do or don't then that would be very helpful.

I don't think these cables have a +5V line.

when i made my lsdj keyboard, the lights would flash dim and it didn't work. but i had connected the cables incorrectly. i swapped them around and it lit up BRIGHT. maybe you have it connected wrong.

Nice one. I would really like it using a dmg port.
does this mod already exist?

That's a good sign... you got power!!!!! I'd just rig up the other wires until you get the keyboard to work (assuming you have all the settings set in LSDJ to sync it up)

Also you dying batteries could be an issue... With LSDJ, a Backlight (if you have one)...and the keyboard will surly drain your battery juice... just saying.... Good luck with this btw!!!!

I think I may need more power. With my CGB (found some batteries) the lights on the keyboard flash dim.

Really?
I thought they could. I have an old GB and a CGB as-well, but no batteries in the house. Ironic with my username. "/

i didn't know an lsdj keyboard would work with a gameboy advance.

Ok, I've joined all the pins and things together with an old link input form a broken CGB.

Bigger pic here

Is this cable acceptable, coz it just won't work with the keyboard.
It's probably just a mistake on my wiring up, or this method won't work because of something technical.

Bigger pic here

When I'm done I'm going to mount the female link port in the keyboard, so no wires to snap.

Thanks.