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  1. #1

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    Learning to repair flash equipment.

    Although I don't have a background in electronics, I would like to learn to repair my broken flash equipment. What are my choices for schools and online opportunities that I might be able to make a 2nd career out of this?

  2. #2

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    Quote Originally Posted by waynecrider
    Although I don't have a background in electronics, I would like to learn to repair my broken flash equipment. What are my choices for schools and online opportunities that I might be able to make a 2nd career out of this?

    I would assume that a course in electronics would enable you to diagnose and repair this equipment. I am guessing that you are speaking of studio strobes.

    The basics are that you will have a rectifier circuit to convert AC to DC current. Additionally you will have a bank of capacitors wired for proportional discharge based on the switching circuit. (The capacitors are present to store the DC) Additionally a trigger circuit to discharge the capacitors into the flash tubes.

  3. #3

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    Just a word of caution: I'm told that the capacitors in a flash unit have enough electricity stored in them to bounce you across the room. Please know what you're doing before you attempt to fix one.

  4. #4
    Ole
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    Quote Originally Posted by jim appleyard
    ... the capacitors in a flash unit have enough electricity stored in them to bounce you across the room...
    It's true - they do. All big high-voltage capacitors do, and the flash ones are among the worst. They can be very, very painful - if you're lucky.
    -- Ole Tjugen, Luddite Elitist
    Norway

  5. #5

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    Quote Originally Posted by jim appleyard
    Just a word of caution: I'm told that the capacitors in a flash unit have enough electricity stored in them to bounce you across the room. Please know what you're doing before you attempt to fix one.
    I don't know what their discharge voltage is, but I have been unlucky enough to be shocked by a 50 mfd 440 volt a/c capacitor. Just one of the many benefits of being an a/c mechanic for 28 years.

  6. #6
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    The flash caps usually have a little more power. Ones I have worked on were on average about 2200 uF @ 600V in banks of 4. I assumed a power pack I working on, was discharged, but decided to make sure with a screwdriver (me assuming again it was just a small charge left). Scratch one screwdriver as it was spot welded to the cap after the bang Was a bit of a surprise.

  7. #7
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    For whatever it's worth, the charge stored in a *single* small consumer strobe's capacitor is considered to be in the potentially lethal range. Most such will store between 350 V and 450 V when ready to flash, and will still have 200 V or higher even weeks or months after the flash was last powered; they're capable of discharging at more than 1000 amps (until something in the circuit melts or the charge is dissipated). The vibrator/inverter that charges the capacitor has a peak output voltage of around 600 V, though it doesn't source much current -- but some parts of that circuit are high frequency AC (up to a few kilohertz, as I recall), which has its own hazards (deep tissue burns are no fun).

    Even the rechargeable batteries in some units are potentially hazardous -- a 4 cell nickel-cadmium battery pack, even with one bad cell (so unable to operate the flash) can dump enough current through a wedding ring to cost you the finger.

    It's very possible to repair flashes and do it safely, but you need to know stuff about high voltage, capacitor safety, and high current batteries that even most electronic technicians don't seem aware of. Be careful!
    Photography has always fascinated me -- as a child, simply for the magic of capturing an image onto glossy paper with a little box, but as an adult because of the unique juxtaposition of science and art -- the physics of optics, the mechanics of the camera, the chemistry of film and developer, alongside the art in seeing, composing, exposing, processing and printing.

  8. #8

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    I like to tinker and am more interested in repairing my small strobe stuff, not the big battery packs, although I'm sure you can get hurt on the small stuff as well. I think that mostly it's bad bulbs that need to be replaced more then anything. I'm not afraid of electricity, you just have to know the procedure. Since no one really answered the question, I suppose it will be harder to learn then i would think.

    Donald, thanks for the quick low down. I can understand the way you put it.

  9. #9

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    I was thinking of repairing a flash myself at one point. After I read the information in this site I decided that I would leave it to someone with the know how. This site has a a lot of information and links on how and what to do. Take time to read the disclaimer part way down the first page.

    http://repairfaq.ece.drexel.edu/sam/strbfaq.htm#strbdis

    Gord

  10. #10
    127
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    I had a crack at a TINY flash (guide #15, run from AAA batteries - the baby ones).

    The circuit is simple enough - they're not exactly rocket science. Trouble is even this baby was enough to cause me to exercise my anglo-saxon dialect. Seriously painfull, if not dangerous.

    After about three hits (despite discharging, and removing the batteries), I wore rubber gloves, which solved the problem.

    Do not underestimate the kick these things can give out. Anything larger than the one I was playing with would do serious damage.

    Simple removing the power, and/or discharging is NOT sufficient to make them safe.

    Ian

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