Electrovibe No Effect, No Light

[Jonathan1986]

So, this is the 2nd Electrovibe I’ve built, 1st no problems but this one is not working. I used some of the Big Monk mods I didn’t the first time around, Darlington transistor, reliabiLity mod, deeper vibe sound, etc. The bulb is not flashing and the speed led won’t light up, but the Vibe LED comes on. Bypass signal is fine, effect signal dead. Trying to get this done as a Christmas gift, any usual suspects to check???

 

[AceHyzer]

The first thing I’d check is the trimpots. Have you tried adjusting them? If you have and still get nothing, you should inspect all solder joints very closely to ensure you don’t have any solder bridges. Do you have a pic of the underside?
I can’t tell for sure, but is the voltage regulator in the right way?

 

[Jonathan1986]

The first thing I’d check is the trimpots. Have you tried adjusting them? If you have and still get nothing, you should inspect all solder joints very closely to ensure you don’t have any solder bridges. Do you have a pic of the underside?
I can’t tell for sure, but is the voltage regulator in the right way?

So, you were right, voltage regulator was backwards, now that I flipped it around the speed LED will come on now. Unfortunately, bulb still not pulsing.

 

[AceHyzer]

Interesting. If the speed LED is pulsing the LFO is working. And you’ve tried adjusting the trimpots? They directly affect the voltage running to the bulb. Can you check for whether voltage is getting to the bulb itself?
If you use your multimeter to probe the solder joints on the bulb, you should be able to see a fluctuating voltage.
If there is voltage there after adjusting the trimpots but the bulb isn’t lighting up, then you could have a bad bulb.
If there is no voltage at the bulb then backtracking through the circuit to find where it’s dying out would be next.

 

[Jonathan1986]

Well, the Speed LED is not a rate indicator on this pedal but just a switch that cycles between the two different rate pots since this does not have a footpedal to control speed, but it just toggles on and off, doesn't pulse. I've messed the the trimpots, nothing changing anything. But checking voltage to the bulb is probably a good idea and my next move.

 

[Jonathan1986]

Interesting. If the speed LED is pulsing the LFO is working. And you’ve tried adjusting the trimpots? They directly affect the voltage running to the bulb. Can you check for whether voltage is getting to the bulb itself?
If you use your multimeter to probe the solder joints on the bulb, you should be able to see a fluctuating voltage.
If there is voltage there after adjusting the trimpots but the bulb isn’t lighting up, then you could have a bad bulb.
If there is no voltage at the bulb then backtracking through the circuit to find where it’s dying out would be next.

So I checked the voltage, on both solder joints of the bulb it's sitting steady at .745vdc

 

[AceHyzer]

Well, the Speed LED is not a rate indicator on this pedal but just a switch that cycles between the two different rate pots since this does not have a footpedal to control speed, but it just toggles on and off, doesn't pulse. I've messed the the trimpots, nothing changing anything. But checking voltage to the bulb is probably a good idea and my next move.

Oh that’s right, my mistake there I forgot it’s not a rate indicator. Does the voltage to the lamp change when you adjust the trimpots?

 

[Jonathan1986]

Oh that’s right, my mistake there I forgot it’s not a rate indicator. Does the voltage to the lamp change when you adjust the trimpots?

No, adjusting either speedpot makes no change in the voltage seen at the bulb solder joints, remaining steady around .745v

 

[jimilee]

I’m assuming it’s dark when you tested it?

 

[Jonathan1986]

I’m assuming it’s dark when you tested it?

When I initially tested? Yes. Since then, no, but even in a lit room the bulb should still visibly pulse, the first one if I took the cover off you could see the bulb visibly pulse in a lit room.

 

[swelchy]

good possibility that you have something grounding out between your pots and the pcb.. I see you just have tape and not covers.... the solder will poke through the tape and cause shorts...

 

[Jonathan1986]

good possibility that you have something grounding out between your pots and the pcb.. I see you just have tape and not covers.... the solder will poke through the tape and cause shorts...

good possibility that you have something grounding out between your pots and the pcb.. I see you just have tape and not covers.... the solder will poke through the tape and cause shorts...

Never thought of this, I don't have covers for dual gang. I did the same on my last successful unit but now that you mention it, the speed pots on the build are much closer to the board. I could try heating it up with a reflow and try to and back them out a little?

 

[swelchy]

Never thought of this, I don't have covers for dual gang. I did the same on my last successful unit but now that you mention it, the speed pots on the build are much closer to the board. I could try heating it up with a reflow and try to and back them out a little?

if you have solder braid it might be tempting to try... but you'll never get all three pins hot enough at the same time without specialized equipment.. if you have a 3d printer or a buddy with one I have dual gang pot covers downloadable file to print free on thingiverse..
https://www.thingiverse.com/thing:5380729

 

[Jonathan1986]

if you have solder braid it might be tempting to try... but you'll never get all three pins hot enough at the same time without specialized equipment.. if you have a 3d printer or a buddy with one I have dual gang pot covers downloadable file to print free on thingiverse..
https://www.thingiverse.com/thing:5380729

All 6 pins, they’re dual gang pots. I have reflow station, I can do it. If that’s the only lead I have I’m willing to try. I’m out of time for this as a gift for today though, I’ll have to give an IOU and try it tomorrow. Also, Merry Christmas, thanks for the input!

 

[jimilee]

When I initially tested? Yes. Since then, no, but even in a lit room the bulb should still visibly pulse, the first one if I took the cover off you could see the bulb visibly pulse in a lit room.

My bad. I went back and read through it, I thought I read it was pulsing.

 

[Jonathan1986]

Thought I had this solved, but once I got it off the test platform and back into enclosure, the bulb just stays one (doesn't pulse) and the footswitch for the LED won't work now. Ugh, each time I fix something another goes wrong.

 

[Jonathan1986]

Ok, so the Speed control 2 works fine. But Speed control 1 doesn't work and if I hit the footswitch the LED for speed control won't go on anymore. Also, when I try to switch the speed control and switch back, the bulb for stops pulsing, so I have to turn the effect on and off again with the Vibe footswitch and it will start pulsing again but only for Speed 2. I have no idea what's going on anymore, this thing is super finicky.