DD-2/3 repair notes

[At0m49]

THAT is a new fault. I've never heard that particular problem. What is the year of manufacture of the pedal? Use the serial decoder here:
https://serial-number-decoder.com/boss/boss.htm

Says September of 97'.
I'm quite amazed this thing is that old
I guess the serial number it is in the back plate, thats the only number I could find.
Lk28365

[At0m49]

I just found that mine is a dd3a, so that might help

[Pepe]

That is a strange cycling noise. One of my analogue synthesizers had a failure years ago, caused by a faulty multiplexer IC, which resulted in similar sounds. But so far I can see the DD-3A doesn't have a multiplexer IC on its board. Do some of the other ICs work in a similar way?

[At0m49]

Gotta be honest, I don't know. But here's a link with the service manual and respective schematic
Https://stompboxelectronics.com/2023/07 ... boss-dd-3/
I already replaced all of the electrolitic caps and some 100nf caps, but stills the same.

[At0m49]

Gotta be honest, I don't know. But here's a link with the service manual and respective schematic
Https://stompboxelectronics.com/2023/07 ... boss-dd-3/
I already replaced all of the electrolitic caps and some 100nf caps, but stills the same.

In order to access to the schematic you need to press in BOSS DD3A that its colored in green

[At0m49]

I posted this same video in a Facebook group, some people said that it could be the power supply but this happens even with a battery, so I started to think that the culprit may be the DSS306 3 LEG CAPACITOR, am i wrong?

[laurie]

Questions - Was it working and then failed? Or was it like this since you got it? If it was working, what were you doing with it when it failed?

Do you have a multimeter and the skill to use it?

Highly unlikely to be the DSS306.

[At0m49]

I bought it from some guy, he said that it was working before it started failing, the guy told me that suddenly started to make that.
Yes, I do know ho to solder, replace components, and know how to test them, my multimeter has a capacimeter if that helps.
I took one whole day replacing electrolitic caps an some of the 100n caps, but it stills the same.

[laurie]

OK, thanks. In 20 years I've never heard a fault like this in a DD-3, so it might take some time to track down (if it is even possible to do that remotely).

Let's check some basic voltages. With the pedal powered on using a battery, measure the voltage at both sides of the footswitch. One side should be 0V, the other +5V. This will confirm the +5V rail is working.

[At0m49]

OK, thanks. In 20 years I've never heard a fault like this in a DD-3, so it might take some time to track down (if it is even possible to do that remotely).

Let's check some basic voltages. With the pedal powered on using a battery, measure the voltage at both sides of the footswitch. One side should be 0V, the other +5V. This will confirm the +5V rail is working.

Hi! Sorry, I was busy last night, you mean measuring bot pins of the foot switch?
Or you you mean put one side to the ground and then put the positive into one of the pins and then in the other.
Sorry for the confusion