Quote Originally Posted by tkamiya View Post
I don't have much experience with professional flash units but I do have lots of experience with electrolytic capacitors being an electronics hobbyist and a formerly active amateur radio operator. I used to love older equipment.

It is commonly said that unused, electrolytic capacitors dry up and die. I actually have NOT found this to be true.

They seem to degrade used or not and eventually die. When they are used right up to the capacity, they tend to have shorter life. When used in higher temperature, they seem to die sooner. Conservatively rated and used, they tend to last longer. Of course, being a consumer, we don't have a choice on design parameters....

I personally don't worry about this. Use them when I need them. When they die, I just replace them.
Electronics has been a long time hobby of mine as well. When it comes to capacitors "leaking" liquid, they are probably refering to the old waxed caps of the tube days of yesteryear that were built like batteries n were wet.

Modern caps are built much better n leak alot less due to metal casings n special directional expansion slots to keep em from exploding like bombs n catch fire as they once did.

I had an old studio 4 head Balcor that used 16 huge caps the size of dry cells. When that thing finally went the tops of a few caps blew n sounded like a welder with a stuck rod for a couple of seconds, that high voltage hummmmmm, then POP!.. lights out in the building. The stech of electronic smoke like a florecent balast cooking n the main entrance circuit breaker checked out. When I opened the box to see what the problem was several months later, I followed standard proceedure handeling caps, discharging the remaining uncooked ones, I noticed they were still fiully charged. Balcor diagrams showed a slow bleed circuit but it must be a very slow bleed. So don't think your caps are fully discharged because it has been sitting around for a long time, they do take time to bleed off.

I fired up an old potato masher Sunpack 611 after not using it for 35 years. It whistled as it normally does then settled in to the usual beep beep beep so, out of habbit, I fired it at full power a few times. No problem at all n I have been using it regularly for the past year, even made a battery replacement using a sealed lead acid 6V battery.