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Projects => Tech Help - Projects Page => Topic started by: brucer on May 10, 2014, 05:05:53 AM

Title: My Pork Barrel WAS working ... FIXED!
Post by: brucer on May 10, 2014, 05:05:53 AM
Please help this lowly novice:

I built myself a Pork Barrel.

(http://imageshack.com/a/img836/3964/w35x.jpg)  (http://imageshack.com/a/img838/9231/bvke.jpg)

It worked on my testing rig, then I tried to put it in my too small first etched enclosure (urgh!).

(http://imageshack.com/a/img841/943/3dqk.jpg)

Now it no longer works in the testing rig! (tested it while waiting for a bigger enclosure to arrive, urrrgggh!)

(http://imageshack.com/a/img835/6563/w9s3.jpg)

I measured the following voltages:

IC1 (JRC4558D)

1: 4.54
2: 4.54
3: 4.47
4: 0
5: 4.51
6: 4.54
7: 4.54
8: 9.2

IC2 (TL062)

1: 1.7-7.6
2: 4.52-4.64
3: 3.17-5.99
4: 0
5: 4.52.4.63
6: 3.24
7: 3.27-5.82
8: 9.2

IC3 (MN3101)

1: 6.82
2: 0
3: 0
4: 6.8
5: 6.74
6: 0
7: 5.95
8: 0.45

IC4 (MN3007)

1: 6.87
2: 6.83
3: 3.78
4: 0.45
5: 0
6: 0
7: 5.97
8: 5.32

Q1:
C: 9.18
B: 2.55
E: 3.44

Q2:
C: 9.18
B: 3.88
E: 3.78

Q3:
C: 9.88
B: 3.11
E: 3.55

Q4:
C: 5.09
B: 0.63
E: 0

Q5:
C: 6.0
B: 2.7-4.8
E: 6.8

Does anything stand out?  Something solvable?  Any assistance would be appreciated.  I liked the effect when it worked!

Thanks!
Title: Re: My Pork Barrel WAS working ...
Post by: twin1965 on May 10, 2014, 11:35:29 AM
Boxing it up probably disturbed some wiring or bad solder joint. If it was working before then this is what you need to be looking for.

Do a visual check of the wiring and also check for continuity. Check all the solder joints and see if any are loose or if the solder looks dull and not shiny. Best thing is to reflow all the joints. If there was a cold solder joint then this normally fixes it.

If this doesn't work then you'll need to audio probe the circuit to see where the signal stops and start your troubleshooting from there.

Sent from my GT-I9100 using Tapatalk 2

Title: Re: My Pork Barrel WAS working ...
Post by: rullywowr on May 10, 2014, 04:24:33 PM
Are you using solid or stranded wire?  Solid may break inside the insulation. Also as mentioned try reflowing all the joints. Get it working on the testing rig again first.  I'm sure you can nail it!
Title: Re: My Pork Barrel WAS working ... FIXED
Post by: brucer on May 10, 2014, 09:34:21 PM
You were right guys.  Thanks!  I did some solder re-flows on the pot leads and now the chorus works fine.  I'd built my own PCB mount pots from solder lug pots and jumper wires.  I guess they got jostled a fair bit when I tried to fit the board in a too small enclosure (I was trying to fit a 3PRR board in too).  :-[  Live and learn.  Thanks again.
Title: Re: My Pork Barrel WAS working ... FIXED!
Post by: twin1965 on May 10, 2014, 10:38:15 PM
Glad you got it working :)

Sent from my GT-I9100 using Tapatalk 2

Title: Re: My Pork Barrel WAS working ... FIXED!
Post by: rullywowr on May 10, 2014, 10:40:57 PM
Excellent work!  If it worked before you boxed it...it couldn't be too far off the mark. :)