Loss of Signal Over Time with Pedal

[nwilderman]

I've recently accomplished my first DIY-build of a bluesbreaker overdrive pedal and have ran it looks like I've run into some issues with the wiring. The build initially worked as the LED turned on when the pedal was powered and the effects were audible when I played some notes through it. I only managed to play a few notes through the pedal though because the signal seems like its abruptly dropped. It was wired as true bypass and when the pedal is turned off the signal through the amp is audible again. The power cycling of the pedal doesn't really have an effect on its ability to passing signal when the effects are on, I've had to unplug and replug it and turn it on in order for its effect/signal to be passed. I have some frayed ends on a few of the wires and a few of the solder points could have been better placed. I'm currently waiting on a multimeter so I can check the voltages on the board and then plan on reflowing some of the joints. I was wondering though if anyone might have seen this before or has an idea on the specifics of where I would want to look or what the problem could stem from. I've attached some reference photos of the build and the schematic that it came from. Thanks in advance!

[GibsonGM]

Welcome to the forum!   A symptom like this is often a drifting bias voltage R14/R5, R4  pins 3 + 5 of the IC.  If you have no meter, I would check the part values and solder joints in those areas.  Esp the color bands on R15/R5, 47k, so yellow violet orange - hard to see on the blue resistors tho.   Look for cold joints, ones that need more solder....  Make sure C11 has the " - " to ground.  Be sure the IC is seated in its socket.    That's basically the first thing we have to do to debug, anyway!    And audio probe can be made easily if you have an extra cap, and may tell which stage the problem is in (pin 3, 1, 5, or 7 can help locate where the trouble starts).   

https://www.diystompboxes.com/pedals/debug.html   

That fact you pass any sound is good, it means the problem isn't serious, just another 'builder error' we all encounter!!

Edit after merlin's comment below - did you try it on battery??  I assumed you did, assuming is a no no


Can you take a pic of the top of the board flat on a table so we can read all the part numbers and see those resistors?  Thx.

[merlinb]

Are you using an external power supply? Almost sounds like the circuit is drawing excessive current that makes the voltage regulator overheat and shut down after a few seconds.
C5 the right way around? R5/14 the correct values?

[antonis]

If it was on breadboard, I should disconnect Tone/Volume AC GND for checking purpose..

P.S. Welcome..!! 

[Gainiac]

Welcome!  I think all the above suggestions are possibilities, I'll add that I've seen this symptom (a gradual loss of audio) a couple times from iffy solder joints.  If the connection is just barely being made, even the slight heat that your circuit generates can be enough to open the circuit.  In any case, easy enough to check just spray the back of the board with freeze spray (compressed air keyboard duster works) while everything is plugged in and see if your audio comes back. 

[intripped]

looking at the pics, i'd say bad solder joints as well.
the joints on the PCB look good, but all the wires are badly soldered: on jacks, footswitch, probably pots (i can't say from the pics), and wires on the PCB as well.

pre-tinning the wires could be of some help.
another suggestion: be sure to simultaneously touch with the iron-tip the two surfaces/objects that you're soldering.

on the jacks, it looks like you've not heated the jack surface enough.

pay attention with the footswitch, because it doesn't stand the soldering-iron heat for long.

one last suggestion: if you're using a cheap soldering iron, do to yourself a BIG gift, and buy a soldering station with adjustable temperature: a cheap (around 40$, maybe less) soldering station is a hundred times better than a cheap soldering iron; you'll forget about bad solder joints.

[nwilderman]

Thank you all for the warm welcome wishes. I went through the build earlier today whilst cleaning up the wires and re-soldering them through the top of the board instead of the bottom. C5/C11 were placed the correct way. The existing capacitors/resistors on the board were reflowed and additional solder was added to ensure that proper connections were being made. I shortened most of the wires and re-soldered them onto the foot switch but noticed some melting occurring and some pins moving around, I'm not sure if that's a problem or not because it's still able to turn on. It was plugged in and this time no there was no sound passed through. I had it open and plugged into the guitar/amp and was wiggling the wires to see if this time it was maybe a loose connection or something and either I, G1, G2, G3 resulted in some static going through the amp a brief moment where it sounded like a really overdriven guitar being played through it. Those I'll probably look into narrowing down and reflowing tomorrow. G1-G3 are involved with the gain so I'm not sure why those would affect the ability to produce the audio.

While I was typing this and looking at the diagram I also noticed that there is a location for a jumper under G2. Any idea if something like missing this could result in the no sound being produced?

I'll check out the joints some more tomorrow and reflow the ones I feel still need it the most and get back to you all. Really appreciate all the help guys!

PDF of the Board
http://www.generalguitargadgets.com/pdf/ggg_mbb_lo.pdf

[Keppy]

While I was typing this and looking at the diagram I also noticed that there is a location for a jumper under G2. Any idea if something like missing this could result in the no sound being produced?

Definitely. I'm amazed you got even a few notes with that missing. That jumper provides the DC feedback path that stabilizes the opamp, and without it the output of the opamp eventually will drift to maximum or minimum voltage and stay there.

Get that jumper in there and see if that fixes it. I notice that there's a second jumper on the layout near the center, so double-check for that one too!

[bluebunny]

. . . but noticed some melting occurring and some pins moving around, I'm not sure if that's a problem or not

It's quite easy to melt the stuff that holds the pins in a switch, enough to allow the pins and the mechanism within to move and stop the switch from working.  If it still works, you've got lucky, but in general you need to have a hot iron and be in and out within a couple of seconds - no more.  And try to avoid having to desolder/resolder.