Build Your Own Clone Message Board

Hello,

I have completed my 27V boost, and when I use it, it makes a horrible garbled noise when engaged. The notes play, but they are either very quiet or very loud depending on how hard I strum. When bypassed, it sounds normal. When I first plugged it in, the 7660S got very hot, so I unplugged it. When I plugged it back in, it wasn't hot anymore.

https://imgur.com/vcMtk0D
https://imgur.com/x0CQ4fL

I have carefully checked for any solder bridges and confirmed that all the components are in the right place. Based on another post here from someone with the same issue, it sounds like an issue with one or both ICs. Any guidance is appreciated.

Do you have a multimeter and know how to take DC voltage measurements with it?

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

I have a meter and I'm sure I can figure out how to take the reading.

Here's a leg up for you on how to do that:

Set your multimeter to the DC voltage mode, indicated by a solid line above a dotted one. Use the 20VDC range setting if it's not an auto-ranging meter. Your power source needs to be connected to the pedal and there needs to be a cable in the input jack. If the pedal is assembled into the metal enclosure, put the black probe into one of the corner screw bosses of the enclosure--this is your ground connection. If the "guts" are out of the enclosure, use the sleeve tab of the input jack for the ground connection. Then touch the red probe to each point that you want to measure. See image below for the numbering of the pins. Report your results here.

Keep in mind that because this circuit uses a charge pump IC (the 7660S) to generate a ~27V voltage range, some of the IC pins will show NEGATIVE voltage values, so watch for that possibility in your results.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Just to make sure I understand, do I need to do this with the ICs in place or removed?

With IC's in place.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Readings are as follows. None of the results were negative. I used a multimeter with the setting pictured. I inserted a cable into the input jack and touched the black lead to the sleeve contact and the red lead to pins.

https://imgur.com/a/FxfDFnf

7660S
1. 9.35
2. 8.75
3. 0.00
4. 7.13
5. 5.08
6. 9.25
7. 8.75
8. 9.32

TL072
1. 5.02
2. 4.94
3. 4.63
4. 5.06
5. 5.06
6. 5.08
7. 5.11
8. 8.30

Thanks for your help.

Looks like the 7660S burned out (probably an internal short) and will need to be replaced. Contact sales@buildyourownclone.com and they'll get a free replacement out to you ASAP.

Do NOT attempt to remove the old 7660S from the PCB in one piece, as this is very difficult to do without damaging the eyelets. Snip off the 8 legs as close to the body as you can and then desolder them one at a time. Clean the old solder out of the eyelets with a solder sucker and/or desoldering braid (links below) and then install the new IC.

https://www.amazon.com/TBBSC-Desolderin ... B08XQF9WYV

https://www.amazon.com/gp/product/B008O9VLA2/

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2