Boss OC2 - lights on but nobody home

[Statusman]

Hoping someone cleverer than me can suggest something - or maybe this has happened before!

I've got a Boss OC2 (Taiwan version), reasonably new as they go. The light comes on as it should when on battery or mains power but there is absolutely nothing getting through, direct sound or effect, so no difference when switch is on or off.
I've had the back off and the jack connections through to the PCB look fine as to the sockets themselves - the plugs seem to be making a decent contact.

Anyone come across this before or have any obvious things to try?

Thanks in advance

Simon

[Dad3353]

Has this once been working, and now doesn't, or has it never worked since you had it..?

[gelfin]

Just checking, are you connecting the correct way round. i.e. in and out the right direction.

[Sibob]

[quote name='gelfin' timestamp='1461927555' post='3038779']
Just checking, are you connecting the correct way round. i.e. in and out the right direction.
[/quote]

This sounds silly, but I've had a few people do this with pedals I've built for them, certainly worth checking!
If plugged in correctly, and all volumes (octaves and direct) are up full, and still no signal. I'd pop it along to a pedal repairer. I recommend Owen Electronics, did a cracking job on my Line6 DL4: http://www.owenelectronics.co.uk

Si

[Statusman]

Thanks everyone for your replies. To confirm, I acquired this from EvilBay as not working so took a bit of a punt on getting it going but it is in great condition so thought it was worth a look...

Definitely connecting the right way - I did just double check though!

Simon

[Dad3353]

The most likely failure would be the foot switch, I'd say. Can you open it up and simulate its switching, by shorting out the relevant terminals..? The part that switches the led works, but maybe not the rest..?

[Statusman]

Tried bypassing the switch but still absolutely nothing. Time to get the meter out this weekend me thinks! Nothing obvious on the board, loose or burnt etc...

[JapanAxe]

Boss pedals use FET switching, operated by a single switch contact. The signal runs through a buffer whether or not the effect is engaged. I would be looking at tracing the signal through that path, and first thing to check would be the wires going between the in and out sockets and the main circuit board.

Here's the schematic:

Edited April 30, 2016 by JapanAxe