GGG Fuzz Face Almost No Output- Desperate for help

[Electric Warrior]

Resistance would be the same either way. Funny.
7.4k would be nearly 10% tolerance. Aren't you using 1% metal film resistors?

With 7.4k, the voltages should look much better now...

[j_flanders]

Now that I'm checking it, I'm getting almost 9k and 9.3k with the multimeter leads swapped (negative/common on Q2 C, pos on resistor)... does this make sense to y'all? It doesn't to me

Are you perhaps measuring the resistance while the circuit is powered by the 9V?

[nicholasvbest]

Damn, I was measuring resistance with the circuit powered... good catch, feeling silly.

I get almost perfectly 8.2 and 8.5k from my resistors now.

Q2 C is still at 9V!

[Electric Warrior]

That leaves us with the fuzz pot, as PRR had suggested.

How much resistance do you measure between Q2's emitter and ground?

[nicholasvbest]

That leaves us with the fuzz pot, as PRR had suggested.

How much resistance do you measure between Q2's emitter and ground?

75K

[Electric Warrior]

Way too much. Have you checked if the fuzz pot actually is a 1k pot?

[nicholasvbest]

Sorry, I double checked my measurement and got "-74.8" in my multimeter's 200k range, and "-7.6" in my multimeter's 2k range, can only get a measurement with the + lead on ground and the - lead on Q2 E... this is a 75k measurement right? And we want to see somewhere inside of 1k, because that's the Fuzz pot value?

In the Fuzz Face kit, I was given a volume pot clearly marked 500k, and one other pot marked "alpha" (no other markings), so I just used deduction to place it... then again, there were three other pots marked "alpha" shipped with the same order, in a different kit. So they could've gotten mixed up, and I didn't think to measure the pots. Come to think of it, they're three 100k pots (!!) for the Rat, which would make sense to get a 75k reading, and kill all the output, right?

Ok. So I need to remove the Fuzz pot and replace it, and see if I have a 1k pot in my other circuit to swap with. Good call PRR, I was fearing the worst.
Where can I measure to check my potentiometers on my other circuit?

[Electric Warrior]

Alphas are usually labled like this:
https://cdn.sos.sk/productdata/50/b0/03a45053/pom16-lin-10k-b.jpg

You know where the pots are - just measure them

[nicholasvbest]

Have you checked if the fuzz pot actually is a 1k pot?

You know where the pots are - just measure them

Just checked the resistance of all my pots, end to end- they all check out. 1k pot for fuzz, 500k pot for volume, other pedal has appropriate 100k.
Fuzz and volume, end to wiper, each give a smooth resistance sweep as the knob as they should...
Now I'm sad.

[j_flanders]

Sorry, I double checked my measurement and got "-74.8" in my multimeter's 200k range, and "-7.6" in my multimeter's 2k range, can only get a measurement with the + lead on ground and the - lead on Q2 E... this is a 75k measurement right? And we want to see somewhere inside of 1k, because that's the Fuzz pot value?

If you measure negative resistance, the most likely cause is that there's still some voltage in the circuit.
I assume you disconnected the battery, but the capacitors are like batteries, they store voltage.
Either discharge them or disconnect at least one leg of the resistor, pot or capacitor before measuring in circuit.

[Electric Warrior]

Have you checked if the fuzz pot actually is a 1k pot?

You know where the pots are - just measure them

Just checked the resistance of all my pots, end to end- they all check out. 1k pot for fuzz, 500k pot for volume, other pedal has appropriate 100k.
Fuzz and volume, end to wiper, each give a smooth resistance sweep as the knob as they should...
Now I'm sad.

Somewhere between the emitter of Q2 and the pot there must be 74k of resistance causing problems. maybe it's a bad solder joint?

[nicholasvbest]

If you measure negative resistance, the most likely cause is that there's still some voltage in the circuit.
I assume you disconnected the battery, but the capacitors are like batteries, they store voltage.
Either discharge them or disconnect at least one leg of the resistor, pot or capacitor before measuring in circuit.

Ok so the ~70k/~7k (still confused about that) Q2 E to ground resistance measurement was with the battery in and pedal engaged. Does that mean my measurement is bunk then?

I now take the Q2 E to ground measurement again with pedal disconnected (and input jack empty) and the resistance seems to climb to infinity in the Mega ohm range. I'm sorry if I'm sounding dumb- is this user error or what should I temporarily disconnect to check my resistance?

[nicholasvbest]

Guys. It's all over. I found a missing ground wire between my volume pot and ground... which had a ground wire connected to the fuzz pot already. There were supposed to be two wires to the one volume pot lug, so I guess it was easy to miss because there was "already a ground wire there" ... but neither pot had a reference for ground. Check what I mean in the wiring layout.
My voltage looked great with the 8.2k right away... I put the 10k trimpot and 1k fixed resistor back in place and it sounds like a Fuzz Face. I'm pretty stoked, gonna ride this high for the month.

Damn. I hope this 2 page forum pops up whenever anyone Google's "how to waste everyone's time" as a lesson in ignorance
Thank you all again for your time and help. I've learned a ton from y'all. On to the next. I'll post finished pics soon

[PRR]

> anyone Googles "how to waste everyone's time" as a lesson in ignorance

I've wasted weeks on a smaller mistake with more people yammering for studio time.