ChristianHJensen

This usually only happens in two kind of scenarios: Crappy capacitors made with inferior (most often dirty) electrolyte OR if the capacitor has been overheated or charged well above the voltage rating. Quality electrolytic capacitors used withing their specs normally have a very long lifecycle

E.L.. Shapiro Loc: Ottawa, Ontario Canada

It's really a shame that, on this forum, so many interesting and and stimulating conversation that not only address an OPs issues but also bring about good information for others who may be reading on and perhaps can be utilized as a resource, have to end up with rudeness, infantile name -calling and blatant stupidity.

Good thing this is a form of social media with anonymity. I really wonder if some of the folks, who propagate this kinda nonsense, woud do this in face to face actual conversations.

I am beginning to believe that participating in much of this is an unmitigated waste of time and dealing with folks who haven't a modicum of manners or grace is becoming rather disgusting. It seem that "please", "thank you" and any words of kindness have becom obsolete or al lease a rarity, like old film cameras and big bulky strobes.

It also seem that practical day to day experience is of little value to many so it is best to leave all of theses technical questions to all the scientists, engineers, professors and Monday morning quarterbacks!

Perhaps I shoud advise certain folks to discharge a 1000 mfd. @ 1,000 Volt capacitor across their forehead. A little electroconvulsive shock therapy may improve their demeanor.

Gonna go grab me an Alka Seltzer! Ugh

Hamltnblue Loc: Springfield PA

For those who care
https://www.mouser.com/pdfDocs/UCC_ElectrolyticCapacitorTechnicalNotes.pdf

The biggest enemy is heat and use.
The last page of the document addresses occasionally re-charging the cap, not using it.

Leitz Loc: Solms

I'm trying to learn something here, and am looking for facts. It's disappointing to wade through nearly a whole page only to find that much of it is bogus. I'm referring to a post that described a particular procedure for maintaining a capacitor. No brand or model was mentioned so it sounded to me like it was true for all, yet it was at variance with what was quoted from some user's manuals, thus lacking all credibility. I believe that manufacturers know best how their units should be maintained.
As for verbose posts, some folks here don't seem able to write the time of day in less than 10 lines - not pleasant reading.

TriX Loc: Raleigh, NC

E.L. please excuse the bad manners and rudeness of that extremely small percentage of the membership that contributes nothing helpful and continually resorts to mean spirited and snarky remarks. I can only assume that the very few that indulge in this type of behavior must have an extremely unhappy or unfulfilled life and feel the need to share that discomfort with the rest of us rather than dealing with their own issues either with psychotherapy or the electroshock thearapy that you suggest.

For the rest of us, and I believe I speak for the majority, your in-depth and broad knowledge that you are kind and generous enough to share with the forum is valued and greatly appreciated. Thank you, and please don’t give up in disgust, although I can certainly understand your feelings after such an encounter.

Be well,
Chris

rjriggins11 Loc: Colorado Springs, CO

It's an unfortunate side effect of all electrolytic capacitors. Even good quality ones. I've replaced hundreds of bad ones in all makes of power pack and most of them have had good quality caps, with gas. No problem. I've made a living at it from time to time. It's getting electrocuted that takes a little getting used to.

CO

Nikon recommends that their speedlights be taken out once a month and fired a few times to reform the capacitor.

TriX Loc: Raleigh, NC

Since your stated reason is to learn, I would suggest that you first learn to be polite. After that, if you really want to know the answer, forget trying to reconcile the often badly translated manuals, typically written by tech writers rather than engineers. The fact is that all modern flashes utilize electrolytic capacitors for energy storage, and they all have similar characteristics, depending on the technology, regardless of the manufacturer of the flash. So for the actual facts, from those that know, you need only consult the data sheets and technical briefs written by the major capacitor manufacturers, who are the real authority on capacitors. Old and respected manufacturers such as Sprague and Cornell-Dubilier have such material readily available. Just Google storage or shelf life of electrolytic capacitors (or read the Mouser ap note link above), and then you can become an expert on the subject and you won’t have to subject yourself to excessive reading of posts that you find unpleasant.

lschiz Loc: Elgin, IL

Re oil filled. Yes true. Non issue.
Re electrolytic caps, true but they would need to sit unused for years. The main issue is they dry out w/o reg use. Electrolytic caps have a chemical treated dielectric which when dry decreases the effectiveness of filtering and holding a charge. The dielectric deforms allowing opposing plates to touch and this short out.
Prior to my vast experience 😊 as an amateur photographer these last 5 years, I was in electrical engineering. So messed w caps a lot in hi voltage applications. Mainly broadcast transmitting.

ChristianHJensen

Only to a degree - what can certainly happen with the electrolytic capacitor/s in a flash is over-heating. This is a common problem in less-than-well-designed speedlites as many of them do NOT have temperature protection of the charging/discharging circuit. Quality units (such as Metz, Profoto and others) have a temperature monitoring circuit and will throttle the flash - or even lockout operation if the critical parts get too hot. This is specifically done to protect the capacitor/s, the flash tube and the firing circuit.

I am willing to bet that many of the capacitors you have replaced were operated outside (or right at the edge of) the performance parameters - it is unfortunately not uncommon - it does lead to premature deaths (of the electronics)

larryepage Loc: North Texas area

Here's the thing...care and usage of electrolytic capacitors and any of a number of other types of electronic components is (or at least can be) critically different depending on the application...the type of circuit in which they are used.

I have a high-power Heathkit AR1500A stereo receiver which I built in 1974. That was 45 years ago. At the time, it was one of the highest power integrated stereo receivers available...kit or assembled. As a result, it includes a very large power supply, which includes, among a number of other components, two large electrolytic capacitors. The nature of audio amplifiers is that the constantly varying output power level imposes what is called an "AC component" on the power supply filter capacitors. Electrolytic capacitors are very good at a long list of things but they are not good at dealing with these AC components. There are usually small non-polarized capacitors connected in parallel with the big capacitor to "bypass" the AC away from the electrolytic. Helps the capacitor a lot, but can audibly degrade the performance of the power supply. My receiver is not designed with and does not have these bypass capacitors. About 30 years ago, the amp developed a very slight but audible hum, indicating that the filter capacitors were weakening. I replaced them. The interesting thing is that they are still fine today. (Both the original and replacement capacitors were/are premium components made by recognized manufacturers.

Probably one of the absolutely most severe service applications of electrolytic capacitors is as a temporary energy storage device in discharge photographic flash systems. Charging the capacitors to full capacity at or near their full rated voltage, then almost completely discharging them at an extremely high current in an extremely small fraction of a second stresses them greatly every time they are fired. It imposes the ultimate "AC component" on the capacitor. This environment is nothing like the use of these capacitors in an audio system power supply, where they charge to their design voltage and happily stay there all the while, dealing with an occasional "AC component." On top of everything else, in order to save space, most of these capacitors are being used either at or else very close to their rated operating limits.

So no...principles of their operation and care in photographic flash systems cannot be based just on common knowledge of how they may perform or the care they may need in other types of circuits.

So we would all be well-served to rely a little bit (or maybe quite a bit) less on our own arrogant assurance and be a little bit more willing to defer to those who actually know and understand what they are saying. None of us are correct all of the time. I have had to stand corrected a number of times...several times on this forum. But Ed is correct in everything he has said in this discussion. Being willing to listen to him and learn a little something could make life a lot easier and just might save a lot of us quite a bit of headache and maybe even some money.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

When I operated a "flash" repair business, most of my clients were professional photographers. Many of them have significant inventories of equipment and were hard on their gear. Their flash equipment is constant daily use in the studios and oftentimes taken out on location. They are not always stored or transported under ideal conditions. Spare or older equipment that has been replaced by upgraded models would sometimes languish away in a storeroom, attic or basement for protracted periods of time and only pressed into to service in "emergency" situations". Some of the units that were brought in for service looked that they were used in a war zone and yet continued to operate and only needed a minor adjustment. Others required major repairs, upgrades, and/or modifications. Few were entirely beyond repair or in a condition where repairs would not be economically viable and replacement would be a better alternative investment.

I mention this because when the equipment was brought in for service, the photographers were not interested in the science and engineering that went into the components, the innards the capacitors and oftentimes not even the preventative measures to avoid future repairs. The complaints were usually something like "it's dead, it doesn't work anymore, it blew up, it's smoking" The usual order of the day was FIX IT, how much ($)? and, when will it be ready?

Oftentimes the problem was in fact, deformed, or otherwise damaged capacitors. Sometimes other issues in the circuitry failed, such as a defective transformer, voltage multiplier or oscillator circuit that applied excessive voltage to the capacitors. Problems in a defective or malfunctioning rectification circuit could bring alternating current to the capacitors- strobe capacitors don't like AC!

Whatever- we did not do postmortem examinations of the capacitors. The troubleshooting was done, the cause remedied and the capacitors, if found faulty, were replaced.

Some DIY guys tried to repair their own units and shorted out the capacitors with a screwdriver. After a few efforts of doing that, they burned out or dislodged the terminals and messed up a few perfectly good screwdrivers.

Most of the units we serviced were made by reputable time-honored manufacturers. The components were all top-quality parts all within proper tolerances made my well known domestic or imported sources. The folks at Lumadyne, pre-tested each capacitor and marked its exact value in uF on the casing. A 200 w.s unit was actually 200 w.s- the capacitor banks were assembled accordingly and precisely.

There were a few popular units with some original engineering flaws that came in regularly with the same issues. We reported this to the distributor and after a while, the defect was corrected.

I am certainly not the all-time expert on strobes or their capacitors. It's just that our shop, considering the volume of repairs and the nature of these complaints was one heck of a "laboratory" for the gathering of information about PRACTICAL preventative maintenance of flash gear. Many of the expensive repairs were the result of poor maintenance, rough handling and not even following simple instructions that are explained in the user's manual. Imagine, just pulling a lamp head cable out before shutting off the unit can cause a $250. repair- and the warning is silk-screened right on the control panel of the power pack!

As far as this FORUM is concerned, I assume that when an OP poses a logical and straightforward question, he or she has not found the answer in the manual, perhaps does not have a manual and haven't been able to find a solution anywhere else. I don't assume they are lazy or stupid. I don't simply write "read your manual" or "Google it", that is, if I actually have a logical and tried and tested solution. If my solution seems a bit "overkill", that is because it is based on professional standards and solid preventative measures to defeat "Murphy's Law"- a common gremlin in photography. At that point, the OP or anyone else is free to express their own opinion or use or "lose" what I have advised.

If the find my post too long, overly detail or disinteresting, the can skim through it and just extract waht need or just skip it entirely. In the time the waste creating an negative "review" the can go elsewhere to find the answer they prefer.

As for nasty responses: I find that there are some folks on this forum who somehow believe that this site is designed for their personal entertainment and reading enjoyment. Others feel it is a resource to personally address their specific issues and anything beyond that is superfluous and unnecessary- they are treating it as if it is paid, personal consulting service. Some are just garden-variety trolls and just want to aggravate others.

In my own case, perhaps many others who regularly and sincerey contribute good stuff, I need to admit that I am not a professional technical writer nor an English professor. I try my best but I don't have the time to endlessly edit and re-edit my posts. I blurt out what I have to say, do a quick proof-read and go back to my real job. I have done some consulting on government, corporate, and military photographic installations where I have to submit a written report. I have those professionally edited before submission and I am compensated, financially, for my time and costs.

So...I am not gonna pack in this site entirely but I will seriously limit my participation. I will try to confine my contributions to the few specialized sections that I help manage. I understand the site has become a bit overpopulated and too difficult for the administrator to censure all the bad actors, name-callers and so-called trolls. As I stated, I am not an engineer nor a psychologist so I can not fathom why some adults behave like
egotistical self-important children. I find this extremely annoying and unfortunately, it has all exceeded my level of patience.

Later- gator!

n3eg Loc: West coast USA

Sounds like overkill to me, but it won't hurt anything. The minimum is powering up the system at low power and then powering up at high power, both times leaving it on for a few minutes. This is what us ham radio operators do with old tube equipment. All firing the flash does is discharge the capacitors and charge them back up to where they were working before, and since they were working before, this does nothing new.