I’ve received at least one email, and now a comment about sudden flash death induced by or related to LPA design’s Control TL PocketWizards. Moreover, a recent post on Canon rumors has a link to a paper, purportedly produced by LPA Design employees summarizing their investigation into flashes failing.
LPA design claims to have received reports from 120-140 customers that their 580EX II flashes, has been damaged within the past 18 months with similar symptoms. The symptom specifically is the inability for the damaged flash to produce controlled bursts. Lacking the ability to control the output, the flash will make a full power discharge all the time, even for TTL pre-flashes.
TLDR, The Brass Tacks
- The potential exists with at least Canon’s 580Ex II and possibly Nissin’s Di866 (I’ve received a report of a Nissin Di866 being fried in a similar manner) flashes that a failure can occur.
- The failure doesn’t appear to be related to heat buildup, so AC-5 soft shields aren’t a problem.
- The failure appears to be strongly related to an electrical arc formed between the flash tube and the flash’s reflector, eventually frying the controller.
- Replacing the fired controller, doesn’t fix the problem, and the flash will die again, even if it’s never used with a PocketWizard.
- LPA Design claims that failures have happened to less than 0.5% of the MiniTT1/FlexTT5 units, and less than 1% of 580EXII flashes connected.
From my interpretation of the LPA design report, the problem lies in the flash and not the PocketWizards.
Moreover, it seems that if your flash exhibits defects that lead to the failure use becomes a consideration. In LPA Design’s tests, the arcing occurred randomly, even in HSS discharges where you would expect to see it in every “pop”.
Finally, it’s entirely likely that as many 580EX II flashes are failing on users who aren’t using PocketWizards at all, but we’re not hearing about it since they either aren’t being used as much or simply are being considered a case of random broken equipment by the users.
A Deeper Analysis
The LPA investigation tracked down the problem to 2 main areas. First, the failure is ultimately noticed when the insulated-gate bipolar transistor (IGBT) that controls the actual flow of current to the flash tube dies. Secondly, it appears that the IGBT dies due to repeated arcing between the flash tube and the reflector behind it.
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