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Commodore 64
August 23rd, 2011, 11:09 AM
I got a Boss HR-2 in the hopes of being able to repair it. It's an intelligent harmonizer pedal that was only made for a few years 1994-1997. I knew going into the deal it had a high pitched squeal. It squeals constantly when engaged. I was hoping it'd be a simple fix. I took it apart last night. There's no bulging caps or anything that outwardly looks like it's fuxored.

There's a bunch of chips on this thing, and none are socketed.

Looking for places to start troubleshooting.
bcdon
August 23rd, 2011, 02:34 PM
Dude, just change the style of music you're playing! Pick squeals are all the rage in metal! :dude

By 'intelligent' does that mean there is a processor/dsp on board? I'd look at changing the capacitors on the power rails.
Commodore 64
August 23rd, 2011, 05:16 PM
I believe there is a a processor/dsp on board. But we're talking 1994 tech.

I will start with those caps on the power rails. Thanks!
bcdon
August 23rd, 2011, 05:37 PM
BTW, how are you powering this? Does it make the same sound when running off a battery?
FrankenFretter
August 23rd, 2011, 08:55 PM
Does it make a sound like Ned Beatty did in Deliverance? If so, check your rheostatic thesamizer, and the flux capacitor. Seriously, I hope you figure it out. I always wondered why you can find tons of octave pedals, but no more harmonizers. I had a rack mount harmonizer in the 80s that was kind of lame, but sometimes I do miss it.
Ch0jin
August 24th, 2011, 02:37 AM
Troubleshooting...

1. Does it make the noise on battery AND/OR external power?
2. Does it make the noise with no input? You might need to insert a signal cable to power the unit if the input is switched like most pedals
3. Do you hear any guitar sound?
4. Does it sound like 50/60Hz hum or is it much higher in frequency?
5. Is it intermittent? In other words, can you give it a knock and the noise cuts in and out?

If the answers are YES/YES, YES, NO, NO and NO. You have a bit of a mission in front of you and I'd be searching for a schematic. You could of course try switching out caps, but that's going to be really hit and miss. I'd go over the schematic and work systematically through the circuit. Step one in a schematic based diagnosis is pretty much always measure all your rails (power supply voltages) and go from there.