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I just ordered an Insignia ring flash and it seems not to work. When I press the Test button, or short pins on the hot shoe, or use it on camera, all I get is the characteristic sound ("Click") as if the capacitor is getting discharged, but no light is emitted from the flash.

The seller made me a refund and is OK with me not sending the flash back, so I wonder if I can fix it. What are the probable causes of this malfunction? maybe the flash bulb itself is dead?

Update: I disassembled the "head" of the flash and when I press "test" I can see a spark (which is probably the source of the sound). The flash itself is similar to this ring flashring bulb for a flash

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    \$\begingroup\$ Please be careful, those capacitors can deliver nasty shocks. :) \$\endgroup\$
    – junkyardsparkle
    Commented Jan 5, 2017 at 3:16
  • \$\begingroup\$ Where is the spark? \$\endgroup\$
    – Digital Lightcraft
    Commented Jan 5, 2017 at 14:48
  • \$\begingroup\$ i see spark at one end of the bulb, somewhere where electric wire wraps around glass first time \$\endgroup\$
    – aaaaa says reinstate Monica
    Commented Jan 5, 2017 at 21:01
  • \$\begingroup\$ Also, even shorting out a full flash capacitor by accident with a metal tool can literally make your ears ring and your neighbors concerned. \$\endgroup\$
    – rackandboneman
    Commented Sep 14, 2018 at 7:51

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In your flash tube there is a large capacitor connected between the pair of big electrodes in the ends of the circular tube. When ready to operate, there is a large (lethally large!) charge waiting here to be discharged through the gas filled tube. The capacitor charge voltage (several hundred volts) is not enough to initially start the discharge.

To start the discharge a a very high voltage (10 000V or so) spike is applied to the trigger wire that is wrapped around the tube.

Your problem is likely that the wire electrode is too close to something. The trigger pulse shold not spark over anywhere outside of the flash tube. Find where it is sparking and try to increase the distance of the trigger wire to the other feature. A sharp end point sticking out from the trigger wire can also cause this wrong-way flashover. This external sparkover lowers the trigger voltage so it is not enough to ignite the tube.

As others say, when the unit is ready and has not flashed, it contains a lethal electric charge. This is for real, it is not just a routine consumer warning. Be careful.

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