My univox super fuzz pedal kit won't work

[antonis]

According to your photo markings, ALL transistor legs exhibit signal where Q2 Collector and Q4 & Q5 Emitters shouldn't..

[Kevin Mitchell]

Wow this has been onging, huh?!

You need to reflow every single solder joint. I suggest getting some flux so you're not just piling on more solder. Make the iron hotter next time if you can.

Here I am. Wondering why there's only 3 spots with no signal
Orange = red I guess.

You don't have to probe the entire board. Just where the guitar signal travels. Check for guitar signal on the middle pin (base "B") of each transistor. Where it disappears is approximately where the problems are.

The transistors are 2N2222A, correct?

Forgive any ignorance. There's a lot here.

[snow123]

yep im using 2n2222a's.

[snow123]

wait i thought all transistors let the signal through lol. this is how it actually is:


green = signal goes through
red = signal doesnt go through
grey = very, very quiet and weak signal goes through

[Kevin Mitchell]

Did we verify that the transistors have the correct pinout?

[snow123]

im pretty sure yea

[Kevin Mitchell]

I looked up the pinout and got EBC as well as CBE. The transistors in the GGG build document photo are backwards compared to yours.

[snow123]

they're p2n2222a's instead of 2n2222a's.

[snow123]

im using 2n2222a's

[Kevin Mitchell]

What about the note in bold on the first page.

[snow123]

the kit comes with p2n2222as. the p2n2222as are CBE and 2n2222as are EBC.

[Kevin Mitchell]

Can you send me a link to where you had sourced the 2N2222A transistors?

There are photos on google showing mixed info. I'm wondering if the pinout varies between manufacturers. At this point I highly recommend you first hand verify the pinouts.

And again, address the solder joints. Practice makes perfect just don't spend too much time in one spot or you'll lose another pad.

[bluebunny]

We're twelve pages in.  Could we not simply have *tested* the transistor pinouts by now?

[duck_arse]

We're twelve pages in.  Could we not simply have *tested* the transistor pinouts by now?

I thought we'd decided on the transistors a few pages back.

please - can we have a photo of the transistors showing the markings on, nice and clear?

2N = metal can, PN = plastic pack.

[antonis]

We're twelve pages in.  Could we not simply have *tested* the transistor pinouts by now?

We were only eleven pages in just to decide what "grounded item" is..
Those things need their time..

[Kevin Mitchell]

2N = metal can, PN = plastic pack.

Are you sure all 2Ns are metal can?

There's P2N2222A in plastic as well. I wonder if the full part number isn't printed on the package - similar to a lot of PBFREE stuff I have been seeing. Which is why I'm hoping to find a datasheet on the product page that the OP had used.

This is the page that made me suspect pinout variants between manufacturers.
Shows this image;


I could be wrong! The web page could be wrong. But it's best to be 100% so we're not chasing our own tail here. I can appreciate that the OP is still going at it!

[Kevin Mitchell]

snow123, here's how we can determine the pinouts with a multimeter. It's best to use one of the spare transitors that you presumably have.

With NPN transistors the forward bias of base to emitter is greater than base to collector.
In diode testing setting, put the black probe to the base lead - we know it's pin two in either variant here. Place the red probe on pin one, record the reading. Now place the red probe on pin 3 and record the reading. The higher reading is the emitter.

[duck_arse]

2N = metal can, PN = plastic pack.

Are you sure all 2Ns are metal can?

well you got me there - that's a something I've not seen. any idea the manufacturor? do they have a datasheet?

There's P2N2222A in plastic as well. I wonder if the full part number isn't printed on the package - similar to a lot of PBFREE stuff I have been seeing. Which is why I'm hoping to find a datasheet on the product page that the OP had used.

but a "P2Nxxxx" is neither a PNxxxx nor a 2Nxxxx, it's a rare and specific type P2Nxxxx, probably with a Motorola datasheet somewhere setting out why the differences.

back about page 2 is this pic showing those 2N2222A - are they still fitted?



as for the 2N's only being metal cans, well, I don't know what I know anymore.

[antonis]

In diode testing setting, put the red probe to the base lead ..

   

[Kevin Mitchell]

In diode testing setting, put the red probe to the base lead ..

   

Oops  Fixed it.
The guide I was breaking down went from NPN to PNP without much of a notice.

duck_arse;
I can't find a datasheet for the proclaimed CBE, plastic devices. The photo is pretty generic, found on amazon, ebay, walmart, alibaba. Manufacturer shows "unbranded" almost everywhere. So I can't verify my suspicions, only take the lead from other findings on the web. Which could be wrong. But it's a hell of a mistake for an article.