Weird Power Problem

[kurtlives]

Just finished a pedal. I test that 9V is getting to the PCB I get 0V, super! Anyways I test the bypass and it works but no LED . So it seems like I have a power issue.

O btw this pedal is negative ground and has a battery and DC jack.

Now I have continuity in all the right places and no where I shouldn't. I have wired it all up correctly as far as I can tell. My ideas are busted DC jack or cold solder joint. I checked and tested for shorts, none are present.


So here is what is really weird, I tested the DC voltage between ground and the place where the + of the battery snap connects to the DC jack. Nothing complex here, should get 9V. Nope I get 0V. Almost like there is a break in the battery snap, but I get continuity.

Now when placing one lead on the ground (enclosure) and one lead on the input jacks ring (which has - of battery on it) I get -5.9V.


Any help appreciated...Thanks...
Chris

[brett]

Hi
Wild guess...

should get 9V. Nope I get 0V.

maybe your ground is connected to the +9V.

Now when placing one lead on the ground (enclosure) and one lead on the input jacks ring (which has - of battery on it) I get -5.9V.

also sounds like you've gone +ve ground.

but no LED

another piece of evidence for reversed power (LEDs are diodes).
cheers

[kurtlives]

That's what I thought too...I don't have continuity between ground and the + though.

With a lead plugged into the input I don't get continuity between the leads sleeve and the input jacks ring. Is that normal?

I forgot to test for continuity between the tip of lead and ring. Probably should have done that.

[kurtlives]

Any other ideas?

[petemoore]

  Here's my take on it:
  PS's get put together and each and every step isn't tested along the way, under each and every set of variables possible [conditions of the DC switch and the input jack ring/monoplug/input jack sleeve...switch.
  Also...from personal exp. the switching of which lugs isn't 'mapped' or understood before the component is installed. Having the DC jack w/switch, the DC plug with accessible wires, a DMM [which will need to test many and various points to points, some of them relevant]...a 'map' of the switch when open and closed can emerge. Understanding what the DC jack does 'when' makes it much easier to wire it correctly.
  Same thing for the input jack, you need the right type, and an understanding that the PS circuit in the box must match exactly that of the schematic.
  It's a large chunk to assimilate when looking at a PS circuit w/switches and grounds and...breaking it down may help find the fault. I know that's what I had to do...lift likely wires until I found the fault...sometimes 'this' sometimes reversal of 2 lugs on a jack, wrong jack...hard to tell.