Timmy Clone- Tommy PedalPCB problems

[Big mike 1100]

Still something wrong unfortunately.  No sound when plugged in.  Open to all suggestions!

[willienillie]

Sounds silly, but are you sure you didn't mix up the in and out jacks?  Easy to do when the guts are out and you're essentially looking at everything backwards.

Hard to tell for sure, but in your pics it looks like maybe one jack doesn't have the sleeve connected.

Do you get any noise at all, like a light hiss when the volume is cranked up?  If so, do the gain or tone controls have any effect on the hiss?

Can you post better pics of the front and back of the board, and offboard wiring (including the bypass switch)?

Are you familiar with an audio probe?

[Big mike 1100]

No noise at all.  When the pedal is off, the sound travels through the pedal. When the pedal is engaged the LED comes on- no sound, no hiss.

I have an audio probe and will see how far it goes.  I'll also post pics.

Is there an order I can check to diagnose?

I think it's R1-C1-R2-IC3, but not sure what's next.

[willienillie]

You already have an audio probe, that's great.  Start at the input jack tip, then to the foot switch, then the circuit.  This looks like one of the easiest circuits to probe.  C1 > IC pin 3 > IC pin 1 > treble pot lug 3 > treble pot lug 1 > R5 > IC pin 5 > IC pin 7 > C6 > volume pot lug 3 > volume pot lug 2 > back out to foot switch > output jack tip.

[Big mike 1100]

Just tested with the audio probe and believe I found the culprit.  Broken wire on Lug 2 of the volume switch.  I'll give it the amp/box test tomorrow but I believe that's the problem.  THANKS!!

[Big mike 1100]

So I did the audio test.  Had a few small issues- the main one being that the sound was sporadic between IC1 and IC 3, meaning that sometimes I'd hear sound and sometimes I wouldn't.  I resoldered those points and also replaced the IC chip.  When it was (relatively) consistently getting sound at IC3 I hooked up my guitar and amp (still not boxed yet)

The sound comes through with the pedal on- the volume and treble pots seem to work correctly however I don't believe there's any change with the GAIN pot and little to no difference with the Bass pot. 

I see that the GAIN and BASS part of the schematic seem to pivot off of IC2, which is in between IC1 and IC3 (where my problems seem to originate).

Any thoughts as to what to check next?

[Big mike 1100]

Sorry Willienillie- forgot to post pics of that area.  Please see attached.

[Big mike 1100]

Reposting with the hopes of getting some advice.  Thanks in advance!

[Big mike 1100]

So I've been digging a bit deeper and believe the issue is either the switch or the Bass Pot.  Any suggestions as to how to narrow down the issue?

[11-90-an]

What makes you say the switch is a possible problem?
Also, can you audio-probe pin 1 of the IC? And twiddle the bass pot and see if there's any difference..

[Big mike 1100]

It seemed to sometimes help to put the switch in a different position .  I'll probe and report back!

[Big mike 1100]

I have to dig deeper.  Something is causing the LEDs to keep burning out.  I think I need to check this more carefully. 

[11-90-an]

what's the value of your CLR (Current Limiting Resistor)? maybe make it bigger...

[Big mike 1100]

Sorry- new to CLR- Is CLR value calculated by just measuring the legs of the LED?

[willienillie]

Your CLR is R10, and you used 4.7K as the schematic says.  That would be fine with a standard LED, but for a "high brightness" or "ultrabright" type you may need a higher resistance.  I usually use 47K for those, but most people don't go quite that high.  I just don't like bright LEDs, and more resistance = less current = longer battery life.

[Big mike 1100]

Yup- using a Hi-bright Clear Blue LED but can swap for a regular if it burns out again.  Bought a mixed kit from small bear that has some of each.

I'm audioprobing again after replacing the LED earlier (still hi-bright for now) and there is sound on all 3 gain pot Lugs and no sound on any of the 3 bass lugs.
When I probe IC1 and twiddle the Bass pot there's no change. 

[11-90-an]

can you try reflowing the bass lugs? might just be a cold solder joint...

[Big mike 1100]

I reflowed no change, but there's definitely something weird after IC1.  The gain pot gets sporadic sound.  I reflowed them as well.

[11-90-an]

so the treble pot works...

can you check R4? it should be a 3k3 resistor...

maybe try reflowing everything? take IC out of course..

[Big mike 1100]

I'll reflow everything.  R4 is a 3K3 and C4 is a 1u, which I believe is correct?