Aquababy No Delay [SOLVED]

[Hexjibber]

Hi everyone, just finished up my Aquaboy build and was going through the calibration steps but I'm not getting any delay on pin 3 of IC3, only a quiet high pitched oscillation, despite much tweaking of the bias trimmer. Audio is reaching the output when the effect is engaged but just no delay. I've made no substitutions in terms of parts, been through and checked my IC and electro orientation but currently can't see any issues there. I have to admit I am guilty of boxing it already, I always do and I suppose I've built so many pedals with no issues I've become complacent! Hoping if I post my voltages something may stand out, would appreciate it if anyone can cast a knowing eye over them, thanks!

IC1
1 - 4.62
2 - 4.62
3 - 4.59
4 - 0.00
5 - 4.59
6 - 4.62
7 - 4.62
8 - 9.26

IC2
1 - 0.98
2 - 1.78
3 - 1.78
4 - 0.00
5 - 1.79
6 - 1.76
7 - 3.10
8 - 1.79
9 - 1.79
10 - 2.97
11 - 2.98
12 - 1.79
13 - 9.25
14 - 1.78
15 - 1.78
16 - 0.16

IC3
1 - 9.23
2 - 4.31
3 - 6.73
4 - 6.75
5 - 0.00
6 - 4.38
7 - 1.38
8 - 8.04

IC4
1 - 8.63
2 - 4.31
3 - 0.00
4 - 4.31
5 - 4.31
6 - 4.32
7 - 3.90
8 - 8.05

Q1
E - 3.74
B - 2.99
C - 9.26

Q2
E - 2.50
B - 3.00
C - 9.25

Q3
E - 6.18
B - 6.51
C - 9.26

Q4
E - 5.56
B - 6.05
C - 9.26

[madbean]

Your Vgg voltage is way off. It should read under 1v yet yours is 8v. You need to take a closer look at pin8 of the 3101 and see if there is some kind of soldering bridge or anything that doesn't look right. If you have a different 3101 maybe pop that in and recheck the reading on that pin to see if the clock itself is the issue.

[Hexjibber]

Your Vgg voltage is way off. It should read under 1v yet yours is 8v. You need to take a closer look at pin8 of the 3101 and see if there is some kind of soldering bridge or anything that doesn't look right. If you have a different 3101 maybe pop that in and recheck the reading on that pin to see if the clock itself is the issue.

Thanks for the quick reply Brian, I appreciate it. I'll have a look at the soldering etc in that area, I only have the one 3101 on hand so may order another if that's a possible failure point. Will let you know how I get on! Thanks again!


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[Hexjibber]

Here's the underside of the board, can't see anything suspect around that area so will order another 3101 and see if that gives me some different voltages or results


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[Scruffie]

Your Vgg voltage is way off. It should read under 1v yet yours is 8v.

Almost as if someone had relabelled a MN3102...

You can test that by checking the resistance between Vgg and Power & Ground out of socket. If it be a 3101, the resistance to ground will be smallest, be it a 3102, the other way round.

[Hexjibber]

Success! A new 3101 arrived today, popped it in and its all working like a charm, thanks for the save Brian, much appreciated!