Author Topic: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed  (Read 801 times)

kdagostino

Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« on: January 01, 2022, 09:19:20 PM »
I attempted to build a General Guitar Gadgets Orange Squeezer, and once complete I got no effect. Pedal off I got the uncompressed sound and pedal on nothing. This led me to pulling out the PCB and hooking it directly to the amp to isolate the problem, and still nothing (a slight surging sound if anything). I tried replicating the Testing the Effects image (picture below), but it didnt match up directly with my PCB, because mine didnt have an Output on the PCB. I ran the output to the area labeled G on my PCB (picture below) guessing it was my Ground and Output.

After not working I hooked everything up to a 9 volt and took multimeter readings. None of my multimeter readings match the recommended numbers from the chart (picture below) so I am currently at a loss.

(Colors relate to picture below)
Red - 9.               Brown - 8.52          Black - 8.2
Blue - 3.59           Maroon - 8.53        Lime - 9.05
Orange - 8.3         Purple - 4.44         White - 8.36
Gray - 8.43           Light Blue - 5.76    Dark Gray - 8.89
Pink - ~2.6 3.6     Peach - 2-3










« Last Edit: January 01, 2022, 09:24:20 PM by kdagostino »

Mark Hammer

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #1 on: January 01, 2022, 09:43:01 PM »
Are you certain that the chip is inserted properly?

idy

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #2 on: January 01, 2022, 11:06:16 PM »
Welcome to the forum.

There are a whole series of grounding spots, marked G. Lots off things need G in a stomp boxes, the sleeves of the jacks, pin 1 on the volume pot, the footswitch for the LED, power (sometimes this goes to ring on a jack so plugging in connects power)... but running the output from G will give you nada.

You can see the diagram for that PCB here. http://www.generalguitargadgets.com/pdf/ggg_osq_lo_pot.pdf

The output should be taken from the hole marked O1.

kdagostino

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #3 on: January 02, 2022, 10:47:37 AM »
So to play the PCB through the amp externally the setup should look like this?


Ice-9

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #4 on: January 02, 2022, 11:59:14 AM »
So to play the PCB through the amp externally the setup should look like this?


That picture shows no ground wire to the circuit.  connect a wire from the (sleeve) to ground (G) on the PCB to power the board.
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idy

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #5 on: January 02, 2022, 12:41:01 PM »
When posting voltages, please use a format like the chart you shared of correct voltages, i.e. for all 8 pins of the IC and the transistor also. Decoding the color coded PCB is a bit much.

But first make sure there are ground wires to the needed places!

kdagostino

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #6 on: January 02, 2022, 09:24:49 PM »
OK so I think it is all setup correctly now (pictured below), but still no sound from amp.
Here are the multi meter readings I got.
IC1:                          Q1:                      Q2:
Pin 1 - 8.55              Drain - 9.08         Drain - 9.08
Pin 2 - 8.55              Source - 9.10       Source - 5.08
Pin 3 - 9.04              Gate - 9.10          Gate - 5.08
Pin 4 - 9.04
Pin 5 - 8.55
Pin 6 - 8.55
Pin 7 - 8.22
Pin 8 - 9.10

Thank you everyone!


PRR

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #7 on: January 03, 2022, 01:14:05 AM »
All your voltages seem to be 9V, just about. You expect a range from 9V to zero.

Do you know you have to put a plug in the input(?) jack to turn-on the power?
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kdagostino

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #8 on: January 05, 2022, 02:06:50 PM »
I originally set it up like the below picture, but the pedal only worked while turned off. After some research I found that separating the PCB from everything else was a good way to isolate the problem. I removed the PCB and setup it up to a 9v, and that's where those readings came from.


duck_arse

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #9 on: January 06, 2022, 10:00:14 AM »
it's your build that's not working right, all those diagrams and empty boards we know to be correct. can you please post some photos of the thing that is not working, ie your actual built board, including shots of solder-side and off board wirings?

and also welcome.
.... are you serious?

kdagostino

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #10 on: January 07, 2022, 12:01:37 AM »
Here are the pics of both sides of the PCB. Excuse the soldering job haha.





antonis

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #11 on: January 07, 2022, 03:32:16 AM »
Excuse the soldering job haha.

It's OK with us..
(but definitely not with the effect.,.) :icon_wink:

Plz desolder, clean and reflow all wiring connections without so much stripped wire length..

P.S.
What about that 10k trimmer empty place..??
« Last Edit: January 07, 2022, 03:38:28 AM by antonis »
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bluebunny

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #12 on: January 07, 2022, 03:50:39 AM »
^^ What Antonis said.  There are definitely some questionable joints that need re-doing.  Make sure your iron is hot enough for solder to flow properly.
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idy

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #13 on: January 07, 2022, 10:26:25 AM »
I *think* the empty 10k trimmer is an optional on-board volume trim. He is choosing to use the off board volume control (separate but connected pads.)

ElectricDruid

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #14 on: January 07, 2022, 03:27:27 PM »
Make sure your iron is hot enough for solder to flow properly.

I agree, but it's not just a question of temperature. It's also time. When I was starting out, I'd read loads of things saying "components can be destroyed by too much heat" and I was always trying to do it as fast as possible. But later I learned that's not right. I don't think I've *ever* actually, definitively, fried a component with a soldering iron. What I *did* do thousands of times is undercook joints so they don't flow properly. A second more heat makes all the difference.

Ice-9

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #15 on: January 08, 2022, 11:36:32 AM »
Make sure your iron is hot enough for solder to flow properly.

I agree, but it's not just a question of temperature. It's also time. When I was starting out, I'd read loads of things saying "components can be destroyed by too much heat" and I was always trying to do it as fast as possible. But later I learned that's not right. I don't think I've *ever* actually, definitively, fried a component with a soldering iron. What I *did* do thousands of times is undercook joints so they don't flow properly. A second more heat makes all the difference.

I agree, other than polystyrene caps, you can actually watch them melt.
www.stanleyfx.co.uk

Sanity: doing the same thing over and over again and expecting the same result. Mick Taylor

Please at least have 1 forum post before sending me a PM demanding something.

pinkjimiphoton

Re: Calling all Stompbox Gurus Troubleshoot Diagnosis Needed
« Reply #16 on: January 10, 2022, 01:54:14 PM »
Here are the pics of both sides of the PCB. Excuse the soldering job haha.





yeah,,,,,.......
you need to reflow this. it looks like lead free that hasn't been heated enough, as noted. that would kill the whole thing dead.

but paul nails it, too... you have almost the same voltage everywhere, which indicates you got something wrong in the power supply. i'm not familiar with the circuit or this pcb, but i'd start by sucking each connection, and reflowing with a hot iron and good solder.

you want your joints to be nice and shiny, not grainy. hard to do with lead free, but still doable.

one other suggestion... use thicker solder. a lot of people use .02 solder, and you have to really feed it in fast to get a good joint. its fine for smd stuff and really close traces, but in general, i find a .8 solder <about the size of a guitar e string, as opposed to a d string> works better for most stuff.
you can flow in more solder quicker, with less heat required.

keep us posted, mate
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