My univox super fuzz pedal kit won't work

Started by snow123, March 09, 2021, 04:57:33 PM

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snow123


bluebunny

I think that what Iain means is that the track is no longer there.  I think what you're seeing is a "shadow" of where the track used to be.  (If it's really there, you should be able to tin it.)  So you need to make the connection yourself: as Iain suggests, use a  small piece of wire to join the adjacent good pad to the component lead poking through into the damaged area.
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Ohm's Law - much like Coles Law, but with less cabbage...

aelling

There is also a place where the track has been lifted completely off the board pulling the trace up too.



snow123


antonis

Put a smear of epoxy glue around lifted pad and keep it pressed for a short time.. :icon_wink:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

snow123

Quote from: bluebunny on March 21, 2021, 06:42:38 AM
I think that what Iain means is that the track is no longer there.  I think what you're seeing is a "shadow" of where the track used to be.  (If it's really there, you should be able to tin it.)  So you need to make the connection yourself: as Iain suggests, use a  small piece of wire to join the adjacent good pad to the component lead poking through into the damaged area.
would i use some solid core wire for that?

bluebunny

Quote from: snow123 on March 21, 2021, 01:51:15 PM
would i use some solid core wire for that?

Yep.  An off-cut from a resistor would work fine.
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Ohm's Law - much like Coles Law, but with less cabbage...

tl-ww-ext

I saw that transistor orientation was addressed previously so maybe this isn't helpful, but I remember reading this on GGG when I built this kit:

Please Note: The 2N2222A transistors in the kit have a pin designation opposite of
most transistors that we use. So The transistors are mounted opposite of what the
screen-print on the PCB indicates.

http://generalguitargadgets.com/pdf/ggg_superfuzz_instruct.pdf

T

eh la bas ma

#48
Quote from: tl-ww-ext on March 22, 2021, 10:21:41 AM
I saw that transistor orientation was addressed previously so maybe this isn't helpful, but I remember reading this on GGG when I built this kit:

Please Note: The 2N2222A transistors in the kit have a pin designation opposite of
most transistors that we use. So The transistors are mounted opposite of what the
screen-print on the PCB indicates.

http://generalguitargadgets.com/pdf/ggg_superfuzz_instruct.pdf

T

You're right, this is quite confusing.

All transistors in this fuzz are 2n2222a. According to some datasheets i could find, pinout can change depending on manufacturers. I'd suggest to look for the manufacturer, if it's written on yours, or send an email to ask GGG (if you bought the whole kit from them), or some voltage readings will be required to be sure.

two exemples showing different pinout : https://html.alldatasheet.fr/html-pdf/75121/MICRO-ELECTRONICS/2N2222/1445/1/2N2222.html

       https://html.alldatasheet.fr/html-pdf/277968/SECOS/2N2222A/150/1/2N2222A.html
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

PRR

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eh la bas ma

#50
??? I am sorry if I am wrong.

You might be right, but I still see opposite pinout if  I flip the left one's flat side in my head to match the other one: I must be missing something...

Edit : ah, it's viewed from below !
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

duck_arse

#51
the general rule with those [isometric?] pinout drawings is that you can't see the pins when you look at the top of the transistor.

edit: end elevation plan something - I've forgotten all I learnt in tech drawing.
You hold the small basket while I strain the gnat.

snow123

Ok, I swapped out the transistors with regular 2n2222a's and a couple of the caps since they seemed to be damaged.










snow123

#53
and the multimeter readings ive been getting are still kinda random, like some parts will make the MM beep and others wont. but most of the wiring is good, so the issue is somewhere on pcb with the caps and resistors.

Phend

#54
That switch jumper above your thumb does not go to the outside posts like in Arons picture. Which is not to say what you have is incorrect, just an observation.
(That was a few photos back, I see now the things have changed)
Don't let me confuse this thread...........
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When the DIY gets Weird, the Weird turn Pro.

eh la bas ma

#55
When you test the circuit, is it still the same ? There is some sound only in bypassed mode ?

C17 (47uf) looks in bad shape on your picture, It would be safer to test it, to make sure there is no issue with it.
There should be a capacitor testing mode on your multimeter.

Trimmers should be set on 12' when you are testing with your guitar, and turn them carefully (don't touch anything else on the circuit) while playing to hear if there is any change.

Here is a link to help you figure out your NPN transistor's orientation, if there is still doubts : http://www.electricalbasicprojects.com/how-to-identify-npn-and-pnp-transistor-using-multimeter/

I see you have a stereo Input jack. Is there a chance that you used the wrong terminal to solder your IN wire ? here is an exemple: http://www.generalguitargadgets.com/how-to-build-it/building-kits/wiring-input-output-jacks/
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

snow123

Ok, I just swapped out the trimpots and changed out all of the electrolytic caps, and placed a resistor in between the footswitch and led.






snow123

honestly i feel like i should just start over

snow123

like probably just get a new pcb since ive kinda burnt it up quite a bit

eh la bas ma

#59
Did you try to change the footswitch ? It is my last resort when a circuit doesn't work and i don't know why...It worked once or twice.
I wouldn't get my hopes up because the soldering side of your pcb looks like there has been some struggling, but if you have an other 3pdt around, it might worth a try, just in case.

led resistor should be something between 3.3k and 4.7k, If i am not mistaking.

Getting a new pcb without parts means you are willing to desolder everything. It's easily managable with patience and desoldering practice, but I would at least get new transistors as well, because they are heat-sensitive. All your other components are more resistant.

You should use sockets for your transistors next time, these will allow you to easily take them off the pcb, to protect them from heat, while you work on the pcb, or change their orientation if need be, without using an iron. 
It looks like that : https://www.musikding.de/20-Pin-inline-socket
You just push the transistor's legs inside the tiny holes. It can also be useful for diodes or whatever component, if you want to try different things.

I would suggest to start again with a whole new kit, and keep this one for the day you will be more experienced. When you'll have 10 or 20 kits done, you might be able to get this one working and add mods. But this is just an opinion.

Debugging a circuit is easier when you are familiar with multimeter's functions, electronics basics, and when you already have debugged some circuits. The first time debugging is always quite difficult. I'm sure you have already learned a few things about polarity and soldering.

I am sorry we couldn't help you more and get this fuzz working.

Edit : if you couldn't even turn on the led, it could mean that your DC power jack wiring is wrong, or the footswitch wiring is wrong, or the footswitch is defective...or the led wiring is wrong.
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.