Did I Fry The PCB?

[Lowspeid]

I built a StewMac Ghost Drive Klone a couple weeks back. I installed a green LED instead of the clear that came with the kit. It sounded awesome, and had no issues. I wanted a different LED color, so I pulled the board out and put in a new LED (same LED as the green, just a different color). When I started playing it after installing the new LED I was getting a loud pop when engaging the pedal, the pedal was working intermittently, and anytime I moved it it would either make loud noises or stop working. I thought maybe a solder connection on the input jack was poor so I disconnected all the lead wires, sucked the solder from the jacks and power connection, and “started over” with new wires and clean jacks and power adapter. Now it’s worse. When I touch/jiggle the wires on the input jack or power supply I’m getting loud sounds/“thumping” noise.

Did I fry the PCB? Did I fry the jack/power supply? I’m not sure what to do next. I love the pedal (it sounds better than my KTR!), and want to get it working so I can have it on my board, but the popping/thumping sounds it makes when engaged make it unusable. Any help is appreciated!

 

[Peegoo]

The first thing to do is use a meter to test for continuity from each of the power jack's solder pads to the next component on the board. Use the PCB traces to serve as your road map.

 

[Lowspeid]

@Peegoo I’m new to electronics. Would I use the ohms setting on my meter to test for continuity? What does it mean if there is resistance?

 

[Peegoo]

Use the Ohms setting; it should read zero or really close to zero. If it reads OL (open loop), it means the circuit is open or broken.

Most meters have a "continuity beep" function, with a little icon that looks like a speaker or sound waves, and this works great too:

 

[loopfinding]

the klon is buffered bypass (though just switches between the buffer and effect mechanically instead of with a flip flop/FETs like boss) and the stewmac said it cloned that.

if you say the effect is intermittent, then it could be something dumb like the switch is wonky. check the switch.

check the two 68k and 100k "anti-pop" resistors on the output.

otherwise maybe a bad cap somewhere.

 

[Lowspeid]

Use the Ohms setting; it should read zero or really close to zero. If it reads OL (open loop), it means the circuit is open or broken.

Most meters have a "continuity beep" function, with a little icon that looks like a speaker or sound waves, and this works great too:

Thank you! I’ll check and report back.

 

[Lowspeid]

the klon is buffered bypass (though just switches between the buffer and effect mechanically instead of with a flip flop/FETs like boss) and the stewmac said it cloned that.

if you say the effect is intermittent, then it could be something dumb like the switch is wonky. check the switch.

check the two 68k and 100k "anti-pop" resistors on the output.

otherwise maybe a bad cap somewhere.

How do I check the switch? I set my meter to ohms and some pads had resistance, some had open loops. Is there a simple to read print out of what things should be reading?

 

[owlexifry]

the dpdt switch is probably cooked. the ‘intermittency’ sounds like a bad switch.
those little mini switches sadly are very heat sensitive and often fail if exposed to too much heat.
i’ve had so many fail on me.

buy a new switch and carefully solder it in.
maybe look into the use of liquid flux (this has helped me at least)

Edit:
looks like the stewmac kit uses a regular 3PDT stomp switch, should be more robust than what i was thinking of, but still, it's possible it could fail.
also, check the ground(-) connections are all ok (i once had a dodgy/missed ground that caused thumping and popping when any leads were touched).
use the continuity function on your multimeter to check that the grounds are all consistent across the entire circuit

 

[Lowspeid]

@Peegoo @loopfinding & @owlexifry,
Thank you for your help. I found a grounding issue with the DC power jack (big surprise, right?), had a couple iron burns on the wires connecting the pcb to the jacks, and didn’t like the look of the input jack connectors (way too much solder).
So I:
*Sucked as much of the solder off the jacks as I could
*removed all the wires connecting the pcb to the jacks and threw them in the trash
*re-wired the pcb-to-jack wiring with new wire, and took my time making sure everything was clean
*made sure not to use too much solder on the jack lugs

It now works PERFECTLY (I shook it, slapped it, and even kicked it around a little just to make sure it was tough enough). In all honestly I think it sounds better than my KTR. I’m pretty sure the Ghost is going on my board, and the KTR is going on the shelf.

Again, thank you guys!

 

[Peegoo]

It now works PERFECTLY (I shook it, slapped it, and even kicked it around a little just to make sure it was tough enough).

Well now that is kick-ass!

And it's even sweeter because you diagnosed and fixed the problem yourself. You can put this experience into your toolbag and use it for lots of other stuff as well.

Bravo Zulu!

 

[owlexifry]

I found a grounding issue with the DC power jack

It now works PERFECTLY

excellent! good to hear it’s resolved, nice work

 

[ahiddentableau]

Glad you got it sorted, but you should learn how to build and use a continuity tester sooner rather than later. I recommend the type you plug into an amp because it gives you additional information as you trace through the circuit. Learning to troubleshoot builds is a major part of this hobby.

Madbean has a great tutorial on this on the resources page.

https://www.madbeanpedals.com/tutorials/downloads/Making_a_Prototyping_Rig.pdf

The relevant part is on pages 6-15.

 

[Wound_Up]

Why don't you put the original LED back in and see if it goes back to normal?

Different color LED's need different amounts of current to operate, also. So most times you can't just swap one color for another because theyre "the same led but a different color". They need different supply current to operate. So you probabky needed to adjust the circuit as well when you replaced the LED.

Put the old one back in and see what happens.

 

[bobrast]

I built a StewMac Ghost Drive Klone a couple weeks back. I installed a green LED instead of the clear that came with the kit. It sounded awesome, and had no issues. I wanted a different LED color, so I pulled the board out and put in a new LED (same LED as the green, just a different color). When I started playing it after installing the new LED I was getting a loud pop when engaging the pedal, the pedal was working intermittently, and anytime I moved it it would either make loud noises or stop working. I thought maybe a solder connection on the input jack was poor so I disconnected all the lead wires, sucked the solder from the jacks and power connection, and “started over” with new wires and clean jacks and power adapter. Now it’s worse. When I touch/jiggle the wires on the input jack or power supply I’m getting loud sounds/“thumping” noise.

Did I fry the PCB? Did I fry the jack/power supply? I’m not sure what to do next. I love the pedal (it sounds better than my KTR!), and want to

The first thing to do is use a meter to test for continuity from each of the power jack's solder pads to the next component on the board. Use the PCB traces to serve as your road map.

Not sure if reply is the proper thread to express this. But I too bought a StewMac Ghost Drive kit and carefully solderered away until I accidentally soldered in a pair of 47uf resistors where I should have placed 4.7ufs. I had to unsolder those and place the correct parts. So back to the question; by doing that did I fry the PCB board through overheating? After finishing, I placed the battery and hooked up guitar cable to Ghost to amp and got nothing. Is there a thread to guide me through testing the circuit and troubleshooting.

 

[bobrast]

Thanks for the tip. Working on it.