Fancy a challenge?

[Papa_lazerous]

I bought a Boss DD-3 off of ebay that was listed as working sometimes....... Well they lied what they meant was works never lol

Its an early one from what I can tell a web site I saw explained the different revisions, it led me to believe its a version 1 board.  I cant find a schem as yet.

When powering up on a 9v adaptor I stomp it and nothing on the LED, then after a few stomps the LED will come on but not latch on then after maybe 10 seconds it starts to latch as designed, the whole time I have power connected I get a clean sound as if its stuck in bypass mode. regardless of the led state.


I have ripped the back off and there where a few joints that had gone a bit fuzzy and suspect I have re melted them to no avail, I am thinking its part of the FET switching on the bypass at fault or maybe a bad cap hence taking 10 seconds or so to stabalise on the LED. But I remember reading a review on harmony central a while ago saying they take 10 seconds or so to settle down so perhaps not.  I am thinking I should be able to probe it and see for basic things like LFO to see if there is life and try and trick the bypass into kicking off. I have a scope aswell as a trusty audio probe.  a bit at a loss though as I cant find a schem and no nothing about a pedal as complex as this

I really need someone to throw me a bone here if you are willing

[Papa_lazerous]

I have come up with this........

http://www.stinkfoot.se/andreas/diy/articles/DD3.htm

I am defo Version 1, under the pic of the gut shot I am the one on the left, still no luck on the Schematic I cant believe there isnt one out there

[The French connection]

Here's the schematics of the DD-2, i think it's the same as your vesion minus the direct out instead of the stereo out...Hope it will helps

DAn

[The French connection]

ooppps the link: http://www.freeinfosociety.com/electronics/schemview.php?id=126

[ayayay!]

There's some old DS-1's that do the same thing.  I used to have a Version 1 DD-3 and it did the same thing.  So it's normal.

But is it working once the Check light goes solid? 

[Papa_lazerous]

No its not working once the light goes solid, I possibly didnt clarify that properly as I was posting in a rush earlier (always a mistake)

Even once the LED has settled down the output is DRY no delay its as if its bypassed all the time that or something in the pedal is dead

[Papa_lazerous]

Here's the schematics of the DD-2, i think it's the same as your vesion minus the direct out instead of the stereo out...Hope it will helps

DAn

Thanks for that link I had seen it already and noted it was similar, certainly the main chip is the same, I guess I can use that to help me at least get somewhere.

Now just to decipher the pinout of the chip and see if there is any life 

[Papa_lazerous]

Ok I have made a break through I think

first of all as stated above the DD2 schem is near on the same infact its labelled DD-2/3 so I have probed with the scope and the chip is alive and kicking its definately running and recieving a clock signal aswell.

Also it states on the schem that there is a 5 second mute from power on, so thats nothing to worry about.

Here is th part that I am struggling with...... If I turn the delay up full with E.level and F.back full (so any delay is going to be noticable) and I turn the amp up loud I play a note and I do get a delay although the volume of it is extremely faint indeed.

I need the expertise of someone who understands this more than me.  it doesnt use a standard by-pass like other Boss pedals.  I really need pointers on this. I am thinking I need to look around the output of the expander to see if I get sa strong "wet" singal and then the output of E'level pot "wiper" before it feeds into the De'phasis mixer to see if I have a strong signal there.  What to do about it I am not sure guidance is going to be the kep if anyone can give me some.  RG if you are about it would be appreciated