News:

Forum may be experiencing issues.

Main Menu

Board playing funny buggers - Edit: SUCCESS!!!

Started by Willybomb, May 08, 2017, 09:18:37 AM

Previous topic - Next topic

Willybomb

Gudday all.  I have that issue we've all had every now and again - the pcb that will only work when it's held or pressed a certain way.

http://www.madbeanpedals.com/forum/index.php?topic=24145.msg235775#msg235775

I'd replaced the Smalltime delay with a Mimik instead, as I was getting all sorts of random problems as per above.  The Mimik works fine with the tap tempo.

Anyway, I wasn't happy with the Glam (PT based choruses are a bit... iffy... for me), or the Equinox II (basically a spring style reverb) so I replaced them yesterday with a Pork Barrel pcb and a Rub-a-dub on vero.

And wouldn't you know it, now the Smoothie only works intermittently, only working if it's on an angle I haven't worked out and have been unable to keep it in.

I've touched up the solder joints, and it all seems good.  I've insulated the bottom of the board with double sided tape.  Indeed, sometimes it works perfectly, to not so well (slower than set) or no phasing at all.  It always passes signal - it's just not always effected.  Any ideas on how to fix this, or a sequence to try?

Thanks,
Willy.


somnif

The fact that settings wonder around make me think the problem is somewhere around the pots. Any chance wires are shifting and making contact between lugs (and or enclosure)?

gordo

I've run into this before and it's usually been a weird solder joint.  The toughest one to figure out wasn't solved till I pulled a chip (which was known good so I wasn't concerned with it) only to find that a leg had broken off and was randomly making contact.  In other words...it's going to be something goofy like that.

The WORST is when you fix it, but you don't know what you did that fixed it....
Gordy Power
How loud is too loud?  What?

Willybomb

I'm thinking I'll replace the ICs.  I seem to be getting good voltages from everything though.  I'm wondering if I haven't cracked something internally in the board itself.

Willybomb

#4
So it turns out R11 (or R19, one of those two) was grounding against the enclosure.  I insulated that using some double sided tape to a)insulate and b) help hold the board in place against that inner wall....

In other news changing the boards seems to have gotten rid of the LED tick that was coming through from the tap tempo.