Mach 1 working intermittently

[Scottydogg123]

Finished my first pedal build but have a problem. Pedal only works intermittently. Here’s what’s happening.
- When on, it occasionally works fine, other times it dulls the sound. A signal is passed through but without gain and volume boost.
- LED is working and switched on/off correctly.
- the issue seems to be unrelated to the switch.

will need to have another look but could something be contacting the metal case and causing this?

 

[TSReppe]

Hey dude!

could you take another picture more close up? And a picture of the board?
Does it work fine in bypass?

First thing I’d do is a reflow on the solderjoints. Got really frustrated with a pedal that would die after 15min connected to power. In the end it was just a joint that needed a reflow, even though it looked fine.

 

[Scottydogg123]

Thanks I’ll try that. I assume there is no way of narrowing the problem joint down?

 

[TSReppe]

Thanks I’ll try that. I assume there is no way of narrowing the problem joint down?

Probably not, but start with those solderjoints on your volumepot. They don’t look good. Also doublecheck that all your resistors have the correct value.
This could be helpful: https://www.electroschematics.com/resistor-color-codes/

 

[TSReppe]

Measure voltage on leg 8 of the IC to make sure it gets the necessary juice.

 

[BuddytheReow]

The board may need to get good scrubbing with isopropyl alcohol

 

[BeeSharp]

Resolder your volume pot and rotate your input jack so it doesn't touch the back of your drive pot

 

[Chuck D. Bones]

Let's see the back side of the board.

 

[Barry]

Is there a dustcover on the pot under the board?

 

[BeeSharp]

Is there a dustcover on the pot under the board?

Good call!

 

[Scottydogg123]

Lots of good suggestions. Thanks all. Dust cover, no. Should there be? What do u recommend using?