Hey Ray,

I just checked online. It doesn't look like the mod is out there anymore. Here's the basics:

What you'll need:

Screwdriver.
Two 1/4 mono audio jacks (what you plug a guitar cord into). Available at any Radio Shack.
Soldering iron.
Copper wire - about 4 feet.

Set up shop on a kitchen, dining room or picnic table. You'll need enough room for the keyboard plus the keyboard's lid opened up over the top.

The mod is easy. (Probably easier than hot wiring a car - although I've never tried ;-O ).
Remove any batteries from the keyboard.
Turn the keyboard face down.
Use a long magnetic screw driver to remove all of the screws from the bottom. Place them in a small cup or sandwich bag so that you don't lose any.
Turn the keyboard face up with the keys facing you.
Lift up on the cover underneath of the keyboard to loosen it up from the bottom of the frame.
Do the same thing with the back but do not remove the lid yet.
Now pull the lid forward a few inches so that the key bed (the part with the felt on top) is moved away from the bottom of the keyboard and towards you.

This is one of the most delicate steps:
*Slowly* tilt the lid back away from you. There are some ribbon cables that are held into place with flexible hook holders inside the guts of the keyboard.

Open these slowly and release the ribbon cables so that you can freely tip the lid back onto the table.

Plug the keyboard into the power brick. (Don't worry - the Casios use low DC voltage).
Now locate the volume knob or slider on the lid. Find the 6 wires coming out of there and the ribbon cable that connects to a small circuit board.
Find the black battery terminal.

Drill holes large enough to hold the audio jacks that you purchased into the back of the lid. Make sure that they
are situated in a spot where they will not interfere with lid closure. You can usually find a spot near where the other pedals and jacks are located.

Cut a wire long enough to go from the black battery terminal to one of the jack grounds.

Solder the ground into place on one jack.
Cut another small wire to go from the ground on one jack to the other jack and solder/series the two grounds together.

Cut two more wires long enough to reach from the jacks to the volume slider/pot or to the circuit board where
the ribbon cable from the volume pot connects (either way works).

Solder the two wires to the hot lead on each jack (do not connect them).

Plug an amplifier into the left jack.

Pull up any sound on the keyboard and use the mixer to pan the sound hard left. Also, turn off any reverb. This will help you verify that you're not getting any bleed through across channels. (Consult the manual if you don't know how to do this).

Use the "hot" wire from the left jack to probe for the sound on the panel that connects to the volume pot. You'll know that you have the right one because:

1. It makes a sound.
2. It is not distorted.
3. It varies in volume when you turn the volume knob up and down.
4. It varies in volume when you change the pan.

If all of the items above are true, you have found the correct contact point. Keep trying until you're certain of the point to connect the wire (It's a one in 6 choice - you'll figure it out).

Once you have located the right connection point, solder the hot wire into place, pan hard right and start the process over again with the right jack.

If you've done everything correctly, you should be able to put one sound on the Left channel and another on the Right without interference between the two channels.

If all goes well. Slowly put your keyboard back together. Take extra care when you're positioning the ribbon cables and locking them back into place.

Before you put the screws back in, double check to make sure that everything is still working properly and that no wires are caught in the lid or will obstruct the screw holes when you screw the lid back onto the keyboard. (I once got all the way to the end, and actually cut one of the ribbon connectors when I screwed right through the middle of one. Take your time and be careful.

I've done this mod at least 6 times on various Casios over the past 10 years.

Good luck,
Bill

Last edited by Bill Lyons; 07/30/10 03:14 PM.