I’ve been frustrated because the kick pedal on my Roland HD-1 only functions intermittently. I listed the HD-1 on CraigsList, and a guy came over to check it out, but he was not satisfied with the reliability of the pedal. I called Roland to see about replacing the resistive sensor in the pedal, but they only sell the complete pedal assembly, at $220. Since the current value of my HD-1 is approximately $300, this makes no sense at all.
I discovered that you can purchase an equivalent/replacement resistor from Pololu (http://www.pololu.com/catalog/product/1696) or under $10 which works just fine. If you want to repair your HD-1, this is the procedure.
Tilt the HD-1 on its side, unplug the kick, and remove the kick assembly, as shown below:
Remove the four phillips screws and one hex screw:
This will separate the black housing from the base:
The spring connecting the silver pedal and the black housing may come loose or fall out: don’t worry about it. In fact, you may want to remove it to make what follows easier.
You will see the black rubber piece that is used to transfer the pedal force onto the resistor. The resistor is at the end of the plastic ribbon, and is sandwiched between two pieces of clear plastic. You can just cut the plastic ribbon clean across the clear plastic pieces.
Note that the black rubber piece may end up inside the black metal housing. The plastic stud that holds the rubber in place was originally part of the black metal housing, but snapped off when I removed the housing. No big deal, since it is pressed in place when the housing is replaced.
The other end of the plastic strip/ribbon goes into the black metal housing. You can remove the black metal heel plate to see what is going on inside:
Pull the plastic ribbon from the connector and discard it. Remove the 1/4″ plug using a set of socket wrenches.
Get two light gauge wires about a foot long and twist them into a pair. Solder one end of each wire to the resistor:
Solder the other two ends to the PC board attached to the 1/4″ jack. Note that the photo is incorrect: only solder the green wire to the first (left) of the two solder connections:
Put the 1/4″ connector back into the black metal housing:
Replace the black metal heel:
Place the new resistor sensor on top of the plastic sheet where the old one was, centering it on the end of the white strip coming from the rubber bumper. Tape it in place with clear plastic shipping tape. Placement may be different with your pedal.
Re-attach the black metal housing using the five screws and then attach the entire pedal assembly back on to the HD-1. If the spring that connects the pedal to the housing came loose, it is easy to re-attach. Just put the open end of the spring into the pedal and hook it on the receiver: