Current Lover Debug

[scdesigns]

Had this one bugging me for a while now, not sure whats up. Just get hum from my AC, nothing else.

Here's some pic's (Second pic is of the recomended bridge from the build doc);




Thanks for any help i can get ahead of time.

[Scruffie]

Voltages on all IC pins and when you say AC... you mean AC to DC right?

3007 or 3207? I spy a couple of suspect looking solder joints too.

[scdesigns]

Yea i mean my 9v one spot, its a lil noisey and the circuit seems to be amplifying it, i have listed all the IC voltages aswell as the label from the IC itself. Think my flash is just highlighting some flux and making the solder joint look a lil suspect, from my eye's they seem fine (this is like my 50th pedal build).

Some of these values rise and fall, so im assuming this is the function of the circuit so i have used the peak voltage.

IC1: JRC4558D

1. 4.25
2. 4.26
3. 2.12
4. 0
-
5. 8.47
6. 4.21
7. 4.24
8. 3.85

IC2: MN3207

1. 0
2. 4.19
3. 2.16
4. 8.15
-
5. 8.47
6. 4.19
7. 3.63
8. 3.67

IC3: CD4049UBE

1. 8.48
2. 4.21
3. 4.21
4. 4.22
5. 4.22
6. 4.21
7. 4.18
8. 0
-
9. 4.20
10. 4.22
11. 4.21
12. 4.20
13. 0
14. 4.29
15. 4.19
16. 0

IC4:GD4013B

1. 4.20
2. 4.22
3. 8.07
4. 0
5. 4.22
6. 0
7. 0
-
8. 0
9. 0
10. 0
11. 0
12. 0
13. 8.5
14. 8.5

IC5: LM324N

1. 4.25
2. 4.25
3. 3.86
4. 8.50
5. 1.81
6. 1.9
7. 3.96
-
8. 0.58
9. 3.82
10. 3.84
11. 0
12. 3.85
13. 4.08
14. 5.15

IC6: LM311P

1. 0
2. 3.8
3. 2.4
4. 0
-
5. 8.5
6. 8.5
7. 8.08
8. 8.5

[Scruffie]

I think you're getting your pin numbering wrong on the 4558 they make a little more sense then, otherwise some how you have supply on the wrong pin. I'll assume that's a mistake.

The reference pins seem low but i'll assume that's down to the impedance of what you're measuring with.

Are the voltages moving on the 324? They should be. But yeah there should be some movement down round the 324/4013 & 311 sorta area so that's normal. Although what varies and what doesn't might lead to some more clues.

The voltages look mostly okay as far as I can see... other than the 4558 actually having those voltages, i'd go with either a short, bridge or the 3207 could be a fake, try it out of circuit, if audio passes, then...

An audio probe might be the way to go here.

[scdesigns]

Here is a re measurement of my 4558

1. 4
2. 4
3. 1.99
4. 0
--
5. 3.61
6. 3.97
7. 3.94
8. 7.93

[scdesigns]

Don't know if this is also worth noting - if i hook this up to my "beavis" board i get no signal through the circuit.

If i remove 9v and ground i get signal through and if i hook up a 9v battery directly to the circuit i get signal but not flanging.

This has me confused/stumped.

[Scruffie]

Don't know if this is also worth noting - if i hook this up to my "beavis" board i get no signal through the circuit.

If i remove 9v and ground i get signal through and if i hook up a 9v battery directly to the circuit i get signal but not flanging.

This has me confused/stumped.

The 4558 looks better there.

The battery thing is odd... make sure your DC jack is wired correctly obviously, perhaps it's dodgy though.

If you can get signal with voltage from a battery, get the DC sorted first.

Where did your MN3207 come from and do you have anything else to test it in?

[scdesigns]

See this is on my proto board that i test all my PCB's, and i just tested my Karate Shop on there perfectly fine.

Im going to source a mn3207 and test that but it could take a while to get delivered, just one question through... do i have the jumper set up as per the note on the layout?

Still can't figure out why i cant test this through my protoboard, im stumped.

[Scruffie]

See this is on my proto board that i test all my PCB's, and i just tested my Karate Shop on there perfectly fine.

Im going to source a mn3207 and test that but it could take a while to get delivered, just one question through... do i have the jumper set up as per the note on the layout?

Still can't figure out why i cant test this through my protoboard, im stumped.

Use an V3207?

I can't see how you've set up the jumpers etc, that may very well be the issue.

Check the value of your zener resistor too.

[scdesigns]

I mean the jumper on the under solder side of the board, i have my mn3207 jumpers set as per the layout note.

[Scruffie]

I mean the jumper on the under solder side of the board, i have my mn3207 jumpers set as per the layout note.

Yes you've done that wrong so it is the zener trying to pull current.

"Simply connect the bottom lead (anode) of D4 to the C6/D5 junction."

No jumper used, unsolder the bottom lead.