I should preface this post by saying that my SPD-S is way out of warranty. I bought it used off ebay and it has served my well (once I reloaded the factory install) right up until it was rained on (along with the rest of my cherished gear) at a street dance by band was playing last summer. Ever since then my SPD-S has had a noticeable hum or whine to it. At least that's when I first noticed it.
I had been getting by at gigs by having the sound guy put a gate on it. That really worked well but certainly wasn't a cure for the long term. It was very much present and annoying at rehearsals.
I make my living as a computer geek and thanks to that experience, I had enough courage to pull my SPD-S apart with the assistance of my coworker, Greg, who has tons of hands on knowledge about circuit boards. Here's what we found.
Those little pop can looking things are called capacitors. They are all supposed to be nice and clean and flat on top. These were swollen and leaky. Luckily, the caps have all of the information you need right on the side of them. Listed is the voltage and micro-farads. We ordered the replacement caps online.
When we got them, Greg went to work with his trusty soldering gun. One by one, he pulled out the bad caps and replaced them with the new ones.
Here's a pic with all new caps installed.
Here are all the bad ones he pulled out.
Here are some random pics of the SPD-S being open and exposed. Kind of scary isn't it?
Now here's the part where we have it all back together and powered on. Not only did it boot up, the thing actually works. Here's the kicker. THE HUM/WHINE IS GONE!!!!
The parts for this repair cost a whopping $10 (I ordered double what I needed, BTW) plus $5 shipping. All the disassembly, soldering and reassembly took about an hour and a half if you don't count the part where we waited a few days for the new caps to come in. I don't know what it would have cost if I had put it in the shop but I'm pretty sure I saved myself a bundle.