madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: greyscales on February 14, 2012, 06:40:32 PM

Title: 1590A Sabertooth Debug
Post by: greyscales on February 14, 2012, 06:40:32 PM
I'm having problems with this 1590A layout of a Woolly Mammoth by Lacesensor. (for the layout, search the build reports)

Everything looks right, I've grounded both the input and output, and I'm not even using a switch yet.

Here are pictures of the board:

(http://img96.imageshack.us/img96/9439/img2237m.jpg) (http://imageshack.us/photo/my-images/96/img2237m.jpg/)

(http://img821.imageshack.us/img821/8711/img2235t.jpg) (http://imageshack.us/photo/my-images/821/img2235t.jpg/)

Any help would be appreciated. I'm not great with a DMM, unfortunately.
Title: Re: 1590A Sabertooth Debug
Post by: jkokura on February 14, 2012, 06:47:06 PM
Maybe it would help if you could give us more details? You're having a problem - what kind of problem? What steps have you taken on your own so far? Have you worked any of the debugging steps at all?

Jacob
Title: Re: 1590A Sabertooth Debug
Post by: greyscales on February 14, 2012, 06:50:07 PM
Honestly I can't tell you what's happening because nothing is really happening. I get a little bit of hiss as I turn up the output, but that's all.
Title: Re: 1590A Sabertooth Debug
Post by: jkokura on February 14, 2012, 07:23:38 PM
That's the sort of info we need to know though.

So no signal, just hiss?

The problems could be pretty wide. Have you checked your parts, checked the layout, done anything?

Have you got an audio probe? Where does your signal stop?

Jacob
Title: Re: 1590A Sabertooth Debug
Post by: greyscales on February 14, 2012, 08:01:50 PM
I'm actually not even getting one now.  ???
It was the kind you would naturally get when you turn a pedal all the way up.

I've checked the parts and layout, checked for continuity between the rows to make sure there are no bridges, but couldn't spot anything wrong.

I'll keep trying things, but I don't have an audio probe. I think it might be time to get one though.
Title: Re: 1590A Sabertooth Debug
Post by: greyscales on February 14, 2012, 08:16:25 PM
I just reflowed all of the joints, but nothing happened.

Are the polar caps the right way? It's kind of hard to tell on the schematic, which I'm linking now.

http://www.madbeanpedals.com/forum/index.php?topic=3338.0 (http://www.madbeanpedals.com/forum/index.php?topic=3338.0)

Also, I tried checking the voltage on the transistors. I got a read, but I'm not really sure what they mean or if they are right for that matter.
Title: Re: 1590A Sabertooth Debug
Post by: LaceSensor on February 15, 2012, 04:23:48 PM
the caps you have them the right way
check all cuts
check all joints
check for solder bridges

and build this
http://www.diystompboxes.com/pedals/debug.html


its verified layout, so should work.
If for some reason you fail to get it working let me know ill build you one for cost of parts and shipping. (probably $5)
Title: Re: 1590A Sabertooth Debug
Post by: greyscales on February 16, 2012, 07:44:07 PM
I tried working on this circuit today, reflowing all of the joints, cutting the tracks again, making sure no bridges were happening.

It still doesn't really work. However, I made a video showing what it is doing. Maybe this will help someone help me.  ???

Title: Re: 1590A Sabertooth Debug
Post by: jkokura on February 16, 2012, 08:22:43 PM
At this point, the only tool I would rely on would be an audio probe. As you've not been very specific on what you have done at this point, I'll remind you to not assume you have the right parts in there. From what I can see you've built it correctly, but I can't verify your wiring, nor the parts I can't read in the build.

One thing to mention - did you verify your transistor pinouts are the same as expected in the layout?

Jacob