madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: LateCentury on February 27, 2017, 08:23:24 PM

Title: Testing rig woes.
Post by: LateCentury on February 27, 2017, 08:23:24 PM
I thought I would finally make myself a testing rig after having too many problems with boxing a non-working build first. Yeah, I know.  :-[ I cannibalized an A/B switch box I made as the case. I thought I had everything correct here but it does not seem to work. It passes the bypass signal fine, but when powering up and switching on a board that should be work, I get nothing. I've traced the wires more times than I can count and it looks like it SHOULD work! I've even tested the switch for continuity. All pins show continuity between middle-top and middle-bottom.

I've got an alligator clip for the board input, board output and ground, then positive and ground for the jack. The boards that I have tested power up and I can touch the L wire from the board to the resistor in the case and It lights up. Am I missing anything?

(https://c1.staticflickr.com/4/3730/33027857951_c12ab198a9_b.jpg)
(https://c1.staticflickr.com/3/2807/33027858751_5f390c0d7a_b.jpg)
Title: Re: Testing rig woes.
Post by: jimilee on February 27, 2017, 09:07:44 PM
You gotta wire your D.C. Input to the 1/4" input. You use green for in and yellow for out also, I've done that for several years now.


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Title: Re: Testing rig woes.
Post by: m-Kresol on February 27, 2017, 09:22:04 PM
in addition to Jimi's comment, I'd resolder the output jack sleeve. that joint looks a bit solder starved to me.
Title: Re: Testing rig woes.
Post by: mjg on February 27, 2017, 09:33:32 PM
As Jimi says, connect the DC jack ground to the input ground.  That should get your LED working when you switch the 'effect' on, regardless of if any test board is actually connected up. 

With my test rig, I only have 4 wires to connect - I don't think you will need the white alligator clip once you connect the grounds, because the board ground should connect up between the DC ground and the input/output ground anyway.  One less wire to worry about.  :-)

Some things you could continuity check (apologies if you've already tried these):

- With bypass on: 
   - should be connection between the long bendy bit of the input socket to the same on the output socket. 
   - should be connection between your input socket ground to the green alligator clip.

- With bypass off:
   - should be connection between the long bendy bit of the input socket to the green alligator clip.
   - should be connection between the long bendy bit of the output socket to the yellow alligator clip. 

If any of those don't work as expected, that may help narrow down the problem.
Title: Re: Testing rig woes.
Post by: LateCentury on February 28, 2017, 01:57:04 PM
Thanks! I'll try this out!