What to do? Cram in some LEDs!
Step 1: Open it Up
Step 2: Remove the fret buttons
Step 3: Make new fret buttons
To see how that was done, hop on over to Matt's Instructable on how he made the new pieces here.
Step 4: Drill out holes for the LEDs to go into
Check the height of the LED and you'll know how deep you need to drill. To make sure we didn't go too far we applied some tape to the drill bit. Just drill till you hit the tape and you're golden.
Step 5: Insert the LEDs
A dab of glue and the LEDs stay put.
Step 6: Bend the LED legs
Step 7: Apply copper contact pads
The original design, that you see here, has the copper flat on the board, but after some testing we pulled the copper tape up on one side and folded that end under so as to make a very rough spring.
Step 8: Wire it up - part 1
Here you can see the original plan for the wiring. Each set of five copper pads is wired together and the wires on the right in the photo go to the battery.
Originally, the LEDs were set up so that both legs would have to make contact to light up, but this was giving us erratic results. So instead one leg, and it doesn't matter which, gets soldered to the wires for a constant connection. This drops our possible points of failure and gives us more of a likelihood of seeing pretty lights.
Step 9: Wire it up - part 2
In addition, the copper tape that the LED was still being pushed onto was too flat on the surface of the board. To create a very rough springiness we peeled up one side of the tape and crumpled it a bit or folded it under itself to make it a little thicker. It's crude and not a long-term solution, but it worked for the first run.
Step 10: Pack it all back in and play!
When it all comes together, fire up some Guitar Hero 1, 2, or 3 (screw that 80s edition) and play!
Thanks to Matt for all the work and photos and Adam for the Guitar Hero playing.