SOLVED Duocast not passing audio

[innerlight]

Hello all!
I am once again asking for some guidance on an almost functional build (pics attached). This one came together cleanly and I was really confident it’d just work .
I’ve reflowed all solder points and double checked components. I assume the dot on the OC71 is meant to match with the square on the Pcb?
Anyway, LEDs light up, pots make sounds but no signal passes in low or high modes when engaged. Signal passes when not engaged. Curiously, when I switch between 9 and 27v modes I get a pop and a split second of signal.
Do I audio probe next? Please guide me oh community.

 

[Robert]

I believe you have the transistor installed backwards.

The dot on an OC71 is usually the collector, the square tab on the PCB footprint indicates the emitter and corresponds to the tab on metal can transistors.

 

[innerlight]

Thanks!
Switched that and now I get functionality with something with high output like a synth. All pots have an effect when used this way. However, signal is verrrrrrry weak with a guitar (this is with all trimmers and pots maxed).

 

[innerlight]

I can probe a signal till it hits the TY-141, where it get really really weak. I also replaced the main foot switch just to be sure with no perceptible change.

 

[innerlight]

Ok all here is where I’m at everyone.
I can probe audio right through the circuit till I hit R13. It becomes very weak on R14 and I get nothing from the TY-141P on any pin.
I’ve checked those particular resistors (r14/15) and they’re the right values.
Could a trace be damaged/should I try bridging some connections?
I’ve attached the schematic with the dubious area circled.
If anyone would advise me on where I should jump to where I’d be mighty grateful!
This pedal has some very expensive components so I don’t want to say die!

 

[carlinb17]

R13 is part of your power section. start looking around the section circled in red for sound problems. Is your gain turned all the way down?

 

[innerlight]

Probed that zone, it all seems ok!
Signal is making it to the level two pot but not the output. I ran a wire from the middle leg of the level 2 pot to the out pad on the foot switch Pcb.
Is this bypassing anything?
Now I have signal passing through the pedal, but it’s super weak/quiet and kind of sounds like a gated fuzz. If I strum hard the signal makes it through but soft notes don’t make it.
Any ideas?

 

[innerlight]

R13 is part of your power section. start looking around the section circled in red for sound problems. Is your gain turned all the way down?

Also should I have the gain turned down? I have had all the pots maxed out when probing.

 

[carlinb17]

No keep them up, if you had them down that could be part of the low volume but if they are up that’s not it

 

[innerlight]

I’m not getting any audio when probing any legs of the Ty-141p. Should this be the case?

 

[carlinb17]

I’m not getting any audio when probing any legs of the Ty-141p. Should this be the case?

those are past R14 on the data sheet. Did you look at the components before R14 on the sheet as indicated above?

 

[innerlight]

those are past R14 on the data sheet. Did you look at the components before R14 on the sheet as indicated above?

Hi yeh I did! All seems ok, audio is passing. Any other areas of interest?

 

[carlinb17]

I'm not following you, R14 has very low audio correct? Both sides of R14 or just one side? Both sides of C11 sounds fine as well?

 

[innerlight]

I'm not following you, R14 has very low audio correct? Both sides of R14 or just one side? Both sides of C11 sounds fine as well?

R14 has faint but perceivable audio, C11 is fine too

 

[carlinb17]

Ok c11 connects directly with r14. can you confirm r13 is the correct value and if so can you confirm continuity between the two ? Also you try jumping a wire from the c11 to r14. Just make sure they’re both the connecting to the sides their supposed to be according to tho the schematics.

 

[innerlight]

Ok c11 connects directly with r14. can you confirm r13 is the correct value and if so can you confirm continuity between the two ? Also you try jumping a wire from the c11 to r14. Just make sure they’re both the connecting to the sides their supposed to be according to tho the schematics.

I’m away from home but I will try tomorrow! Thanks so much, excited to see the outcome

 

[innerlight]

Ok! Made a little more progress here.

Ok c11 connects directly with r14. can you confirm r13 is the correct value and if so can you confirm continuity between the two ? Also you try jumping a wire from the c11 to r14. Just make sure they’re both the connecting to the sides their supposed to be according to tho the schematics.

So I checked continuity and values on all of the above. All seemed ok and correct. I then ran a bridge wire between leg 3 of the “level 2” pot to the out of the foot switch (is this bypassing anything??)
It was then sounding super sputtery, so I re-seated the oc71 and switched two of the legs. I’m now getting signal!
Buttttt there are still some issues.

1) both the level 1 and 2 pots don’t have any effect on sound. It seems basically maxed out at all times.
2)the gain pot has verrrry minimal effect on the sound.

Any ideas here? I’m guessing the bridging wire I installed may be in the wrong place?

 

[music6000]

If you have been removing Pots or Components, there is a great possibility that you may have damaged Traces!
Confirm what has been removed & replaced by soldering!

 

[innerlight]

If you have been removing Pots or Components, there is a great possibility that you may have damaged Traces!
Confirm what has been removed & replaced by soldering!

I haven’t removed anything, the only thing I reoriented was the OC71 but that was socketed thankfully!
I did reflow everything, so I may have overheated a trace. But I have no idea where to begin if that’s the case!

 

[carlinb17]

Ok! Made a little more progress here.

So I checked continuity and values on all of the above. All seemed ok and correct. I then ran a bridge wire between leg 3 of the “level 2” pot to the out of the foot switch (is this bypassing anything??)
It was then sounding super sputtery, so I re-seated the oc71 and switched two of the legs. I’m now getting signal!
Buttttt there are still some issues.

1) both the level 1 and 2 pots don’t have any effect on sound. It seems basically maxed out at all times.
2)the gain pot has verrrry minimal effect on the sound.

Any ideas here? I’m guessing the bridging wire I installed may be in the wrong place?

I’m not sure how you ended up there, I had asked you to try a jumper to a suspected trace that seemed it could be bad based upon you saying to c11 it was fine and r14 it was bad