parentheses mini fuzz - no sound or LED lightup

[SurelyTheEnd]

Hey there,

I've built before but not with Pedalpcb. I picked up this kit to build, excited to try it out but after wiring up, there is no sound or functioning LEDs when the pedal's engaged. It passes sound, so that's at least something. The guts look like as below, it's late so I can add other pictures tomorrow. Any initial thoughts? Thanks in advance!

EDIT: So I tried it this morning, but this time with the knobs up from zero because clearly my brain ceases to function after midnight the boost section seems to be working but the rat/octave is only generating white noise. I can turn up the gain/volume/filter and the noise changed accordingly but I get no guitar sound. Any suggestions?

https://imgur.com/a/UYEKGV3

 

[SurelyTheEnd]

So I reversed the diodes that were wired in incorrectly, fired it up and...still no fuzz. Anyone want to give this a look over before I dig out the audio probe?

 

[zgrav]

your build on the pictured side looks pretty clean. make sure your transistors are all making good connections in the sockets and see if that helps.

 

[SurelyTheEnd]

your build on the pictured side looks pretty clean. make sure your transistors are all making good connections in the sockets and see if that helps.

All seem to be seat very well, but still nothing. I'm a bit rusty with a multimeter, what should I be looking for in terms of current flow and indicative hotspots?

 

[zgrav]

You want to start looking at the schematic to see what parts connect to one another, and then use your DMM to see if they are connecting where they are supposed to. That includes making sure that your ground connections are conecting to one another and to the "-" side of your DC power and input and output jacks. Make sure the in and out lugs on your footswitch connect to the right places on your PCB. You also want to change the setting on you DMM to read DC Volts and find out if you are getting power to your board.

 

[Nostradoomus]

What kind of JFETs are you using? Mine only came to life after I used some in spec 2n5458

 

[SurelyTheEnd]

What kind of JFETs are you using? Mine only came to life after I used some in spec 2n5458

I'm using the ones supplied with the kit and as indicated in the build documents, so PF5102 and 2x 2n5089/1x2n5087.

Some current tracing gave the following (all directions looking at the component side of the board):

1) There is power, thought the boost gave this away.
2) Of the rat/octave section, only the left lug of the volume knob picking up from R21 has any current reaching it. All the other knobs have nothing. All turned up to full. Clip switch also reads nothing.
3) Q1 is collecting at the left pin, nothing reading at the middle and right pin.
4) the IC appears to be fully functioning. Power is getting to it and it is reading as to the circuit diagram.
5) R1 reads no signal. Not sure what this means.

 

[SurelyTheEnd]

So there Appears to be nothing going from Q1 which is killing the signal. Reading from left to right, I have 9V on leg one, 0.28 on leg two and 0.00 on leg three. I tries swapping the JFET with the same one and nothing changed. Is this a grounding/powerissue?

 

[Gordo]

I'd pull the board and check over all your solder joints and reflow. Can't hurt to post a pic of the back of the board either to give another pair of eyes. Sounds more like a bad connection if all the parts are right (and nothing jumps out as amiss from that photo).

 

[SurelyTheEnd]

I'd pull the board and check over all your solder joints and reflow. Can't hurt to post a pic of the back of the board either to give another pair of eyes. Sounds more like a bad connection if all the parts are right (and nothing jumps out as amiss from that photo).

Shall do when I get off work. I've reflowed them once already but once more can't hurt. It just seems like power gets to Q1 and then nothing leaves either leg. This is the same for both JFETs in the kit in that position. Seems like something is shunting everything to ground but I can't figure out what :'(

 

[zgrav]

have you tried the board out of the enclosure to see if it works? You may have something shorting to your enclosure when it is boxed.

 

[SurelyTheEnd]

have you tried the board out of the enclosure to see if it works? You may have something shorting to your enclosure when it is boxed.

It does the same thing whether it's out of the enclosure or in it, sadly, so I can eliminate shorts against the enclosure at least...

 

[SurelyTheEnd]

Solder Side of the Board:

https://imgur.com/a/JU2KR54

 

[zgrav]

You need some kind of insulating layer between the pots that go over the board and the board itself. If your pots did not come with little plastic cups that fit over them (Pot condoms), you can put electrical tape on the bottom of the pots AND a piece of cardboard between the pots and the board. (the tape is not enough because it does not take a lot of pressure for one of the sharp points on the PCB to go through the tape.

Folks will want to look under those two pots that are covering up part of the board. You can gently bend them up.

You should also get some ispoproply alcohol (IPA) and a toothbrush to clean that side of the board.

 

[SurelyTheEnd]

You need some kind of insulating layer between the pots that go over the board and the board itself. If your pots did not come with little plastic cups that fit over them (Pot condoms), you can put electrical tape on the bottom of the pots AND a piece of cardboard between the pots and the board. (the tape is not enough because it does not take a lot of pressure for one of the sharp points on the PCB to go through the tape.

Folks will want to look under those two pots that are covering up part of the board. You can gently bend them up.

You should also get some ispoproply alcohol (IPA) and a toothbrush to clean that side of the board.

IPA is on its way. everywhere near me that sells it is strangely in lockdown. Please find below under the pots - Nothing touches, tried putting cardboard between and nothing changed:

https://imgur.com/a/AboYZD3

 

[SurelyTheEnd]

Eliminated the actual switch as the problem, continuity seen between lugs. I am super stumped. Just seems like the signal can't get past Q1 but I'm unsure as to why. Only the distortion pot has any current flow, the others are dead. I am super stumped...

 

[Gordo]

Give the board a good cleaning. Its amazing how flux will hide weird solder joints. Like you say though, might be easier to find Unicorn pee these days. I don't use any insulators either and don't recall ever having grounding issues. At least while it's in the case. Leaning on it while it's out of the case is another matter. I'm still going with funky solder joint. Worst part is you might hit a few of them and never know which one fixed it. Although as long as its fixed...

 

[music6000]

As Gordo suggested, It needs a good cleaning with Isopryl spray & Electronic Cleaner spray.
Be careful not to spray the crap into the Pots.
Have you tinned the Transistors legs, it makes for better contact and grip in the Sockets.
With 18 pins it can go against you, I personally solder all my Transistors.

 

[SurelyTheEnd]

As Gordo suggested, It needs a good cleaning with Isopryl spray & Electronic Cleaner spray.
Be careful not to spray the crap into the Pots.
Have you tinned the Transistors legs, it makes for better contact and grip in the Sockets.
With 18 pins it can go against you, I personally solder all my Transistors.

I'll try tinning the legs and see what happens. Meanwhile, here are the readings i get from the Transistors and the IC:-

Q1
1- 9.12
2- 0.28
3- 0.00

Q2-
1- 3.90
2- 2.36
3- 9.12

Q3
1- 2.43
2- 1.75
3- 2.42

Q4
1- 9.12
2- 0.31
3- 0.00

Q5 (boost - Functioning)
1- 4.65
2- 2.24
3- 0.19

IC (Counter Clockwise from leg 1)
1- 8.90
2- 4.56
3- 2.26
4- 0.00
5- 0.00
6- 4.56
7- 9.12
8- 9.01

 

[SurelyTheEnd]

Made an audio probe and confirmed that the audio comes in, goes up the right leg of Q1 and just never leaves. Not sure why. Jumpers laid according to the schematic don't help. I am fully at a loss now...