Univibe \ NeoVibe question: Bulb not flashing

[greg]

Hello.

I have built the NeoVibe Univibe project from GEOFEX (on an excellent PCB from General Guitar Gadgets.

The unit worked well for about a year, then stopped. The bulb either burned out naturally or from a physical shock (or, perhaps, an electronic failure).

I have replaced the bulb and it is lighting up as it should, but it is not pulsating. Rotating the pot which controls the speed does not cause the lamp to flash at a higher rate - it is simply not flashing at all.

Does anyone know where to begin troubleshooting?

Thanks,

Greg

[R.G.]

You would start troubleshooting
Debugging: What to do when it doesn't work (http://www.diystompboxes.com/smfforum/index.php?topic=29816.0).

In particular, measuring all the DC voltages on the LFO/lamp driver. I think you'll find that the LFO is working OK, but the driver transistor is shorted, killed by the first light bulb shorting when it failed.

But that's a guess. The debugging procedure is much more definitive.

R.G.

Hello.

I have built the NeoVibe Univibe project from GEOFEX (on an excellent PCB from General Guitar Gadgets.

The unit worked well for about a year, then stopped. The bulb either burned out naturally or from a physical shock (or, perhaps, an electronic failure).

I have replaced the bulb and it is lighting up as it should, but it is not pulsating. Rotating the pot which controls the speed does not cause the lamp to flash at a higher rate - it is simply not flashing at all.

Does anyone know where to begin troubleshooting?

Thanks,

Greg

[greg]

Thanks for the response R.G.

I finally have some time to get back into this Univibe issue and will likely begin the "proper" troubleshooting process this weekend.

I do have an additional question or two for you (all)

1) I'd like to add a status LED to the project and am interested to see if I can find out how to make it pulsate in time with the speed (which would simply be cool) - better yet, if it could pulsate constantly - whether the effect is On or Off, that would be even better. It would be more useful as a visual guide of the rate before it is switched On (but then, of course, not useful as a effect On/Off indicator). I'm using a standard 3P3T bypass.

2) My wall wart has kicked the bucket. I believe that I bought it originally through Small Bear. While I am sure I can find something suitable, I'd rather get a known good unit for this (non-noisy, able to handle the current draw, etc). Can anyone make a recommendation?

Thanks in advance,
Greg