Issues with fuzzface

[Distort_Everything]

Hi, recently I made a fuzzface for a customer of mine, I'm not a big builder by any stretch and this is the first time I've came across this issue, heard about it with NPN having a naff cap but usually they're powered by batteries.

It's an NPN silicon, powered by a regular 9v supply, the issue being is that it is cutting out when he is switching it on and sounds like it is blooming into volume. Now I have checked with him he has used two power supplies, same issue, two pedalboards, same issue. It looks like he knocks the pot with his toe on the video posted below, checked it myself and no issue. 

It can't be the power cap because it's running off a 9v supply and technically they're on all the time so it wouldn't be the cap filling with charge, I'm absolutely stumped.

I've checked all the joints, shook it and recreate the issue. He's using it as the first stomp box on his board too before everything including the tuner. Thing is he loves the pedal and really wants it but I really don't know what to do at this point.   

Turns out he's using a standard Tele with no mods into a matamp gt-1

Chain is My Pedal -> Fuzz Factory -> TC Polytune Mini ->Earthquaker Data Corrupter ->
Fuzzrocious Cat Tail ->TC HOF Mini -> Walrus Slo -> Supro Harmonic Trem. 

Cables are Van Damme Parts

Any help is appreciated!

Also after discovering all of that I'm a little jealous of his rig too

Link to video (got his permission to post): https://drive.google.com/file/d/1yQOwTF8gXXip9QzOtz6Qec4D1np-ZXSD/view?usp=sharing

[antonis]

It can't be the power cap

Just desolder that cap (one leg is enough..) to make youself sure..

[duck_arse]

I clicked the link, just cause. can't see nuffink without a login name and password. not me, not at googoo.

how about post some pics of guts and stuff, and I won't even ask about a circuit diagram. but post your circuit diagram as well. also, is the problem the fuzzface or the other thousand devices before the amp input? test guitar/fuzzface/amp chain alone, prove that it isn't something else first.

[Distort_Everything]

It can't be the power cap

Just desolder that cap (one leg is enough..) to make youself sure..

Well the thing is he's sent it back and he isn't close by, it works absolutely fine by itself. I'm gonna try run it through chain of about five or six pedals to see if I can recreate the issue. Just really perplexing me, it's essentially a standard NPN fuzzface with the loud mod (doesn't clean up as well but it's a bit more aggressive) and a further up high pass on the output so it's more mid heavy. I mean where I sold him it, it was running through about four other pedals and that was fine, I'll try what I can and see what happens. Will post a gutshot soon, I mean I've designed the PCBs and never had a problem like this.