I had heard many reports of the drum sets that came with world tour being defective. One guy I know can't get long streaks because the drum set just wasn't of high enough quality. When I set up my drum set it worked great! I was relieved. It seemed the build quality had improved. Not so fast.... Within a few days of some serious rocking out the yellow cymbal failed altogether. I was livid. I knew the stores wouldn't take it back, and it would be weeks to get it shipped and fixed, at a cost. So I did what I do best... I voided the warranty.
I figured the cymbal was a pretty simple piezoelectric device, and anything wrong with it was an easy fix for a geek and his soldering iron. So I set to work. My cymbal was totally non-functional, and broken is a certain way, your mileage may vary.
Step 1: Acquire Testing Ability.
Credit goes to this other instructable on drum set repair for the idea of using the mii freestyle as a test bed. You should start this up and leave it running. Whenever you need to test the cymbal, just plug it in, and see if it works. Very productive!
Step 2: Open Up the Cymbal and Inspect.
There are likely several ways the cymbal can be "broken". This is why the inspection step is necessary. Mine was broken is a specific way. Likely a common way though.
Remove the four screws holding the back of the cymbal on. It's just four small Philips screw, nothing special. Go slow, the screws are going into plastic, and you'll need good threads later to put it back together.
I opened up both my cymbals and compared them. The yellow cymbal clearly had very poor workmanship when compared to the orange cymbal. However, there were no obvious flaws. The solder joints to the piezoelectric looked sound, the circuit board is dead simple, no components at all. Just connects the piezoelectric element to a mini-audio ( mono ) plug.
If you find anything blatantly broken, wire pulled out, plug on board loose... fix that and give the cymbal a test run. If not, move onto the next step.
Step 3: Ensure Functional Piezoelectric Element.
The most complex, but thankfully the toughest part of the cymbal is the piezoelectric. Lets make sure this most important part is functional.
You will find white silicon covering the connections to the piezoelectric element. This must be removed. My finger nail worked fine. I'm sure a small tool would work fine too, just take care not to damage anything.
Get two lengths of wire, thin stranded wire will be fine. I have bags of the stuff. Strip a half inch on both ends of both wires. Solder an end of each wire to the solder pads where the other wires are connected to on the piezoelectric. ( You likely won't be able to solder else where on the piezoelectric, it won't stick. ) I needed pretty high temps on my iron to do this. I will refer to "your" red wire as the wire you soldered to the pad that has the original red wire, and "your" black wire as the other wire.
Now you should have two wires connected to each terminal of the piezoelectric. Using some tape, connect your black wire to the base of the cymbal plug on the drum kit. Then connect your red wire to the tip. Again, just use tape, and put some pressure on it.
Make sure mii freestyle is running as in step 1. Now while everything is connected tap on the piezoelectric with your finger. If you register hits. If not, play around with the taped connection a bit ( It can be finicky. ) This should work... The piezoelectric elements are pretty much indestructible. If you can't get it to work, test for shorts with a multi-meter... Once you have this working, proceed to the next step.
Step 4: Attach Wires to Internal Mini Plug.
Now we know the wires we connected talk correctly from the piezoelectric to the drum set. Now we'll connect those wires to the internal mini-plug at the closest solder pads possible. This eliminates several possible points of failure along the transmission of the signal. In my case, this fixed the cymbal. I'm guessing it will fix many other cymbals that are non-functional as well.
Attached the wires as shown in the image to the solder points on the circuit board. ( For the orange cymbal it will be a mirror image. ) One of the points of failure may be the solder joint from the circuit board to the mini-plug. Because of this, make sure to melt the solder point completely as you attach the wires. This will re-flow the solder and make a good connection.
Now test out your handy work by plugging the cymbal in and tapping on things. If it registers.. Congratulations! you have fixed your cymbal.
Step 5: Reassemble
Now you should be able to put the cover back on. Be careful not to bend your new wires around too much or you might break something. Feel free to use tape to keep things in place. Carefully and slowly screw the four screws back into the symbol back. Remember, these screws are just going into plastic. So as soon as you feel a bit of resistance, the screw is all the way in. You aren't working on a car here.
If you have any questions. Feel free to message me.