Boss DD-3 version B repair help me please.

[ahseng]

Hello all,
I have this Pedal sent in for repair.The unit powers up but no delay effect when engage,only outputting dry sound.This is one of the many technology that's beyond my electronic knowledge.
I have a cheap scope so I feed an 440hz to the input.Tracing that to the output was all I could.Many IC in it I don't understand about.

Has anyone any technical guide such test point/wave form that I could use for repair aid.
I wish I have a second unit to compare it but nope.


Much appreciated any help here

[Enzo]

it is very hard to hear delay on a sine wave, try playing music through it.

[Jazz P Bass]

Here is what I have on the DD3.

The DD3T is the surface mount version.

DD-3.zip

[oc disorder]

Here's the DD3A .. plus a extra picture of layout for the 3A and a picture of the 2/3 one above.

[nickb]

<< DD-3T Service Notes >>

[Mick Bailey]

Make sure the pedal is not in the 'Hold' mode. I've had pedals for repair where the owner thought it wasn't working when set to hold.

Leaking and dried out electrolytics can be a problem with these pedals. Take a look to see if there's any orange/brown crud around any of the caps.

The switching circuit can fail to toggle the effect. Is the LED operating?

[ken]

Here is the schematic for the Boss DD2 or early DD3 long chip version.

Ken