Longshadow Loc: Audubon, PA, United States

Notice I said normally. But they don't swell and/or leak (nothing inside to expand or come out), they either opened or shorted.

In over 45 years, and four flashes, I've never had one go bad or need repair.
(Sometimes they sat for months before use. I've never cycled them on a regular basis, but would occasionally.)
Electrolytics don't die in a few months, it takes years. I still have a flash (PRO 39TA) from ≈1975, has not seen batteries in 10 years. Still works great so far.)

The fact that a flash manual stated to cycle the flash a few times got me wondering...
Do instruction manuals for cameras with built-in flashes recommend taking a dozen shots to "form" the flash capacitor???

Longshadow Loc: Audubon, PA, United States

Oh yes.
I had removed the PC cover on the front left of my camera one time for some reason. Used the flash on the hot shoe and inadvertently got my finger over the PC connector while holding the camera.
Man that sucker hurt! (Couple of hundred volts for the trigger.)

flashbang

THANKS TO ALL!!!

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

I always want to become a professional photographer, ever so I was a kid, that is after I was 8 years old. Before that, I aspired to be a cowboy, a doctor, a policeman and for a while a fireman! Electricity and electronics was always my HOBBY. My dad was an electronics technician, U.S. Navy trained, in radar technology and ran a TV and radio reply business for many decades. I hung around his shop and learned to solder when I was 9 years old. Later on, I helped out in the shop doing minor repairs. I never wanted to follow in dad's footsteps but I learned quite a bit at the shop and garnered respect for high voltage and safety procedures.

As a hobbyist, I build audio systems, qualified for an amateur radio operators license, did most of my own appliance repairs and built a number of studios doing all the electrical wiring to code. Naturally, as a student of photography, an apprentice and a professional photographer my interest in an electronic flash was a natural progression. I always serviced and modified my own equipment, and gained practical knowledge from folks at the America Speedlight Co. (ASCOR), Allied Impex Corp, and PLR (Photolectronic Research Co. ) where I purchased parts for my repair and projects.

In 1971, I met an electronics engineer, circuit designer and professor of electronics technology at a local college. We collaborated on a few projects and decided to open a part-time business specializing in electronic flash custom builds, repairs and modifications. My role was more into the aesthetics in lamp head design, modification and dealing with the photographic requirements of studio operators and other professional photographers.

The business was very successful and although it was a "part-time" venture for both of us, we had 3 full-time technologists working on repairs and builds. We did some BIG installations like 25,000 watt-seconds divided into 12 lamp heads in the local NHL stadium. We were the official Canadian repair depot for 7 brands.

Sadly, my partner became ill and passed away 6 years ago, and I decided to close down the shop and concentrate on my commercial photography business.

So...CAPACITORS! We were ordering them by the case-load. We only used the best brands for replacements and custom builds. Our sources were Siemens, Sprague, and Cornell-Dubilier. We received all the engineering data from the technical representatives and departments of each of those corporations. We had access all the specification of all the capacitor for electronic flash applications as to voltage, capacitance, residual charge and a whole bunch of stuff that is way above my "pay rate". So... when I give advice on practical maintenance of flash gear it is based on a compilation and averages of all that information as well as 50+ years of flash usage as a professional photographer and studio operator.

As an example, it is true that only a few minutes of charging (reforming) is enough to maintain intermittently used flash gear, however, the folks at Sprague used to specify 1 hour. At the shop, we liked to run every unit, on the bench for at least an hour after reforming, repair or capacitor replacement to make certain that everything is up to par and there were no other unfounded issues.

True enough, there are some old "workhorse" strobes, some of the old Metz, Ascor, Dormitzer Synchtron, and others that seem to never die. You find them languishing away in a cellar or attic, plug them in, pop in some new batteries and they fire up like new- or not! There are some relatively newer units that konk out- burn up, blow up and explode! So...my advice is to always take precautions and observe good maintenance habits even if they seem a bit overkill. There is always someone who will say he has four old units that never had any such issues, however, at the old shop, we had 400 that somehow went out with a bang and some, at the most inopportune times, like in the midst of a wedding coverage in a cavernous old church where the sound was significantly acoustically amplified.

At one time there was a (high guide number) competition among strobe manufacturers to pack as much power into a small power supply. The wedding shooters were using the popular ASCOR 444 and Ultrablitz Matador 400 models. Seems the oscillator circuits in both systems, remember that winning sound between shots, were going out of whack and "over-volting" the capacitors and they were literally blowing up on a regular basis.

Current "Speedlights" are truly wonderful devices, however, they are like plastic toys in comparison to some of their ancestors. There is only one main power capacitor in most of these units and it is more likely that one of the other, more complex, exposure control circuits will fail long before the capacitor. On most of the popular portable strobes, back in the day, one of the capacitors was larger than an entire speedlight. Larger and more powerful studio units have banks of capacitors so repairs and replacements could be extremely expensive so maintenance is extremely important. The Ascor Skylighter system had cases that looked like foot-lockers or steamer trunks full of capacitors. If you fire up your unused Speedlight once a month, it should remain in good health for a very long time.

On this forum, there are always long protracted arguments about flash gear- trigger voltages, reforming and general usage and maintenance. Like any other electric/electronic device, common sense and good safety procedures should always apply. Even a small speedlight can harbor damaging or even lethal voltages so please read the manual and safety instruction that come with the unit. If you have an old or second-hand unit without any instructions, there are many online sources where PDFs of the original manuals can be downloaded. If you maintain your flash gear properly, it will give you many years of reliable service without failure or danger.

nadelewitz Loc: Ithaca NY

A number of flash manuals I have seen say to periodically just turn on the flash, let the ready light come on, wait a couple of seconds, and fire (in Manual mode) the flash. Repeat a few times. This procedure ensures the capacitor is being charged and discharged through its range each time.
I have also seen recommendations to turn off the flash when it is fully charged, rather than turning it off in a discharged state.

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

A few minutes and a few flashes shod do it for your unit if that is what the manual states. As I alluded to previously, I prefer a bit more time to make sure everything is functioning.

If you turn the unit off without discharging it, the capacitors will retain a residual charge for a time and that dissipates shortly thereafter. Healthy capacitors always have some residual power even after they are purposely discharged of bled off. That's why, when servicing a unit, we bleed of the capacitors with a resistor and then temporarily shot them out while working on them- soldering, attaching wires to screw terminals, and securing them in place, etc.

Some units will automatically bleed off the capacitors when the power is shut down. Especially on older studio and power pack type units with multiple heads, it is important that the capacitors are discharged (the unit is flashed after switching off the power) before connecting and disconnecting the high voltage cables that lead to the flash heads. Otherwise serious arcing can result and irreparably damage the connectors, both the sockets in the unit and the plugs at the ends of the cables can burn out, carbonize and break off. These connectors are expensive and require many hours of service to remove, resolder and careful re-insulate all of the terminals.

Of course, modern up-to-date studio power pack units may have special circuitry that precludes all of these issues. Nonetheless, it is important to read the manual carefully especially with older units with unknown working procedures. If unsure, discage everything before connecting or disconnecting cables, replacing user changeable flash tubes, changing modeling lamps, making minor repairs or performing maintenance and cleaning tasks.

Leitz Loc: Solms

The quotes from different manuals prove that no one procedure is applicable to all flash units. Best to follow the individual manufacturer's recommendations and ignore the vacuous rhetoric of the "expert" long-winded gasbags.

TriX Loc: Raleigh, NC

That seems unnecessarily unkind and rude - a little civility please.

Leitz Loc: Solms

My bad. Scratch "ignore … " and insert "please ignore … "

ChristianHJensen

No you do not - you just have to charge the capacitor and leave it with a charge (ensured by leaving the flash on) for 10-20 minute a few times a year to avoid the electrolytic capacitor from drying out

BebuLamar

I google on technique to reform the electrolytic capacitor (in general not only for flash) and all of them involve charging the capacitor to its rated voltage for a period of time and then check for leakage. There is no discharge needed. Although as someone pointed out the Nikon recommends to fire the flash several times.

Rab-Eye Loc: Indiana

Touché!

Rab-Eye Loc: Indiana

Nikon says otherwise for their Speedlights.

ChristianHJensen

This guy (me) with Bachelor and Masters degrees in electronics disagree with Mr. Nikon

rjriggins11 Loc: Colorado Springs, CO

Gasses are a byproduct of the electrolytic reaction inside the caps. This will build up over time and cause all kinds of problems whether they are used regularly or not. Eventually the deformed caps will start to crackle and pop and sometimes, they go bang, (loudly).