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Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 145
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 18, 2011 - 10:20 am: | 
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I was recently given a 430EZ and the guy who gave it to me said it worked great last time he used it. When I loaded it up with fresh batteries and tried it out, the first thing I noticed was that it flashed dimly when I hit the test button. Everything else seems to work normally.
I'm thinking that the flash has just sat for too long and the capacitor needs to be reformed. Only problem is this flash has an "auto off" feature, which does not allow for it to remain on for extended periods -- which is necessary to reform the capacitor.
I was thinking that maybe I could open the flash up and apply 6V DC directly to the capacitor contacts and see if that might work. Otherwise, I have no clue really as how to work around this problem.
The 430EZ is an older model, but it's quite powerful and still very useful, even with the modern digital EOS cameras. So it would be nice to get this flash back into operational condition. |
Mareklew
Tinkerer
Username: Mareklew
Post Number: 257
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 18, 2011 - 11:09 am: |
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1) The capacitor gets charged to much more than 6V. More like 300-600V. More important: it stays charged after turning the flash off. Unless you are 1kV-certified/trained technician (or whatever the term used in your country is) stay clear of it.
2) If the ready light lits, the capacitor gets charged up to the nominal voltage. De-formed caps have high leakage and this can prevent them from reaching proper voltage (charge leaks faster than it can be supplied), or leads to fast charge loss (you charge it and it starts charging again in few seconds). IF the ready light goes on and stays on then it's not the case or not the root of the problem at least.
3) This is automatic flash. It flashes only as strong, as necessary for the exposure. Try setting the camera to low ISO, set f:stop to say f:8 and shoot a photo indoors. It might suddenly get much more powerful ;) I don't know if the test button fires it at full power - in my Metz 54 set on Auto the test button fires automatic-exposure shot, so fires only strong enough for a proper exposure, not full blast.
4) If the exposures are off, then something else is wrong.
Marek |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 146
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, November 18, 2011 - 11:21 am: |
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Thanks for the follow-up, Marek. When testing the flash, I do it off-camera and have the flash set to manual modes -- full power and then fractions thereof. I also own a 420EZ, which is very similar to the 430EZ, so I'm familiar with its operation. Off camera, set to manual, full power, it flashes dimly.
I know that a cap holds much more than input voltage. But input voltage IS 6V DC. That was the point I was making. |
Mareklew
Tinkerer
Username: Mareklew
Post Number: 258
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 19, 2011 - 05:02 am: |
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"I could open the flash up and apply 6V DC directly to the capacitor contacts and see if that might work."
Trust me on this one: if applying 6V to the HV-rated cap was to make any difference to it, then the cap is beyond salvation already. That's my point really.
From what you wrote there's something else wrong, or the cap is properly dead (not just de-formed). It might be the tube failing, it might be a contact problem (if so, then I'd suspect the wires going from cap to tube being internally broken and hanging together on an odd thread of copper), the cap being damaged (internal connections severed) or dried-up (age, lack of use and elevated temperatures), or the control-IGBT has slight internal delamination or severed bondwires, or there's some sensor that's bad (resistor divider that reports the cap voltage, lamp current sensor if any, desat detection circuit - if present)...
In any way it's not a trivial task to troubleshoot the circuit and once the culprit was found - to fix it. I'd try to return the unit as it's faulty.
Marek |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 147
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, November 19, 2011 - 12:00 pm: |
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Thanks for the explanation, Marek. Well, nothing lost, really. It was a gift. |
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