Nautilus help? (voltages, etc. added 12/19)

[thesameage]

I have an old nautilus build that I'm finally coming back around to troubleshoot. A friend built it a while back and could never get it to work. I looked it over and it seems like all the joints are good and it's well put together. But... it doesn't filter. It bypasses just fine, and then when you engage the footswitch, it passes a normal signal and the gain works just fine. The only clue that I have is that the only band pass that passes a signal is the lowpass. The other two bands pass no signal. I just went over the switch and it seems to be hooked up correctly.

How should I troubleshoot next?

I just figured out how to do the IC pin voltages and will do that tomorrow night. But if anyone can see anything obvious, let me know.

[madbean]

Nothing obvious. A voltage check and audio probe of IC1C and D is probably in order. It's a little odd to get LP and not the other two. It does make me a bad connection on the switching.

[thesameage]

More info before I do the voltage checks tonight.

When you switch RANGE, the LED dims, but does not seem to react when you play any notes on a bass through the thing, but sound passes equally well on both settings. HI/LO doesn't seem to do anything, but sound passes equally well on both settings. Like I said HP/BP/LP only passes sound on the LP setting. Again, the GAIN pot works very well. And if you turn the SWEEP all the way up you can hear something happening, but nothing major.

It's interesting that it only passes sound with LP, which would make me think that it's a switch issue. I think that the switch is wired up properly, though. I tested the continuity of each wire and held my meter with one side to the A pad on the PCB and confirmed that as I moved the switch, the signal only passed to one each of the LP/BP/HP pads. Maybe it's a problem with the switch itself, but the signal seems to be passing properly.

Anyway... any other thoughts are appreciated. Is is possibly a Vactrol issue? Is there a way to test them? The original builder is very experienced and double checked all of the cap values and reflowed everything before throwing in the towel.

[CaptainPeyote]

This was such a hot-looking board and project.  It kills me that I couldn't make it work right!   

At one time, everything worked... just badly.  I guess I picked at it a bit much if it's more broken than before...

[thesameage]

No worries man, we will get it up and running properly. Can't waste the etched enclosure!

This is the first time I've done these kinds of measurements so factor in user error. I plugged in the pedal (no guitar plugged in), turned on the switch, and took them with my meter: 

A few notes: with the black meter to ground and the red to the 9v pad, I get a reading of 13.04. Also, when I touch the red meter to pin 7 on IC5, the LED goes out, then "recharges" and comes back on.

Also, it appears that the Vactrols are Macron MI1210CLE-R. Could that really be the issue here?

IC1
1: 0
2: 0
3: 0
4: 13.11
5: 0
6: 0
7: 0
8: 0
9: 0
10: 0
11:-12.25
12: 0
13: 0
14: 0

IC2
1: 0
2: 0
3: 0
4: 13.27
5: 0
6: 0
7: 0
8: 9.89
9: 5.34
10: 4.98
11: -12.38
12: 0
13: 0
14: 1.85

IC5
1: 13.47
2: 7.98
3: 0
4: -5.08
5: -12.55
6: 6.82
7: 6.15
8: 13.49

Vact 1
pos: 10.18
neg: 7.72

Vact 2
pos: 10.16
neg: 7.71


D1:
A: 0
K: 1.82

D2:
A: 1.81
K: 3.25

D3:
A: 0
K: 13.64

[thesameage]

Smallbear is down the street and will do a dropoff at a local mail center. Just ordered new vactrols this morning and will pick them up ag 5:30. I'll give that a go, but let me know if anything else looks off.

[thesameage]

Bumping this. Have new vactrols and a new switch that I should have time to install tonight. Based on the readings above, anything else to look into?