Dunlop Fuzzface Mini troubleshoot

Started by BDuguay, July 21, 2017, 01:49:19 PM

Previous topic - Next topic

BDuguay

Has anyone had any experience troubleshooting one of these? I have one that won't pass signal when engaged. Switch is fine and LED comes on but nothing comes out. I got it all apart to discover a bunch of SMT on the underside of the PCB. I've searched for a schematic but no luck.
B.

Plexi

Which version it is?
Does it have the bias trimpot?
To you, buffered bypass sucks tone.
To me, it sucks my balls.

BDuguay

It's the Bonamassa version and yes, it has a trimpot.

Plexi

You're right.
Its vintage in the upper side, and have some smd components and trimpots on the solder side...
Oh...Dunlop...
To you, buffered bypass sucks tone.
To me, it sucks my balls.

Gus

I typed "Bonamassa fuzz face schematic" and found schematics
I would guess the mini is close and if it is not use it to start tracing
Are there trim controls on the backside of the board
Tagboardeffects has voltages

AND then there is the sticky at the top of the pagehttp://www.diystompboxes.com/smfforum/index.php?topic=29816.0

BDuguay

I found that scheme too but it didn't include all the extra SMT transistors and more that are used on the mini version. The trimpot is on the other side of the board along with the rest of the through hole components. I'm sure it's a bias trimpot for the Germanium transistors present.
B.

Gus

Another link for a mini
https://www.thegearpage.net/board/index.php?threads/ffm1-mini-fuzz-face-did-not-like-so-modded-and-i-made-a-video.1402987/

If it looks like note the switch has 6 lugs so the IC and and transistors and diodes might be part of some electronic led drive
Q5 R15 are most likely for the driving the LED

post a picture and/or post the part numbers on the SMDs

BDuguay

I will check this a.s.a.p.
Thanks!
B.