Flash tube glows on White Lightning Ultra 1200??

Hi...I have an ol' White Lightning Ultra 1200 that, after turned on..is fine. Then a pop of the flash and one of the 2 flash tubes actually glows...until the unit gets turned off...which I did immediately after I realized it wasn't the modeling bulb that was producing the bright light.

Freaky.

Then I decided to swap out the flash tubes for a different set...and the exact same thing happened.

Anyone else ever have this happen?

Any ideas as to what could be causing this?

Thanks!

Current is apparently leaking to one tube, when a capacitor should hold that current and only pass it one when triggered. Sounds like it needs to be sent to Buff for service (they have great service, or did when Paul Buff was still alive at least)

Thanks Wilt...I checked their webpage and they no longer do repairs on the Ultra's. Understandable since that product line is over 25 years old...lol!

I don't mind doing some soldering...if anyone has any idea which capacitor I should be looking at, I'd be willing to try to find a replacement part on the interwebs and do it myself...or I have a non-working Ultra 600 that I may be able to pull it out of if it's compatible.

Look carefully at the electrolytic capacitors in the flash. If you see a BULGE in the capacitor (usually at the top). The electrolytic capacitors are the first place I would look.
Generally the electrolytic capacitors will be shaped like a soda can. If the top has been pushed up, you have found the culprit.

Good Luck,

110yd

And take care. Those capacitors can give a great deal of hurt!

I was thinking the triac are leaking/passing the current through. The triac is just before the 10KV circuit on PCB.

ECC233 wrote in post #19165054
And take care. Those capacitors can give a great deal of hurt!

Indeed - in my early days as a technician (Telegraph) we used to wind wire around then, charge them up using a Meggar, and toss them around the workshop like grenades.
Wouldn't be allowed to do that these days!

Thanks. I will take the unit apart tomorrow and get a look at it.

Yeah...I was wondering if there is any way to discharge it before I remove it, if that's what I end up needing to do.

Any way of telling if one is no good by looking at it?

Edit: Just saw a video on YouTube of someone checking a few traics with a multimeter. I suppose I could try that.

...now I want to try this...lol!

Just realized that either one or the other flash tube will randomly remain glowing after a few flash shots. It's mainly on the right side though.

Took the unit apart, took pics, didn't see anything obvious. No bulging capacitors. Cleaned it up, blew out any debris, tried it again and same thing happened.
I guess it's just a situation where I would have to throw parts at it, not sure it would be worth it.

For what it's worth, the button on the circuit breaker is sticking out a little; they're supposed to be flush. It won't push completely back in. Not sure if that has anything to do with the problem.

A tech would probably just hook up an oscilloscope, clip one lead to ground, and the other lead goes to the output of any triac to see if current is coming out when there ought not be.