Hi David thanks alot for your answer, that was very helpful for me. I deal a lot with electronics but have usually no idea whats *exactly* happening inside and could not repair anything.
Now for the big surprise: Curiosity kills the cat (and me) one day: I tried again today with the flash and bingo, after first not showing the ready lamp I just let it sit there for a few minutes and now it works flawless! Pentax gear even continues to works after "the big bang" ;-) greetings Markus -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of David Mann Sent: Saturday, December 02, 2006 8:07 AM To: Pentax-Discuss Mail List Subject: Re: Can a flash explode? On Dec 2, 2006, at 6:03 PM, Markus Maurer wrote: > Just before I tried a test flash, the flash made a really loud bang > and > began to smell, but the display still stayed on faultless. > After I switched it of an on again, a second kind of small > explosion occured > inside the flash and the ready lamp stays off now. It may be possible to diagnose from the smell. A pungent, fish-like odour would probably be caused by an electrolytic capacitor. These tend to be used for the energy storage in a flash, and high-voltage ones can degrade if left unused for a long time. If it was more of a burned-toast smell, then it was probably a semiconductor. A bit of energy stored in the capacitors can make semiconductor failures quite spectacular :) > I think that is is definitly broken now but I wonder if that thing > could > have exploded in my hand and injure me severly? I doubt it. If it was a capacitor, these are designed with a specially weakened part of the case to controllably vent gases before a serious explosion can occur. They can still make a decent bang, but it's nowhere near as big as it could otherwise be. A semiconductor probably won't blow up with sufficient energy to penetrate a plastic casing... not until you get into serious power electronics where a lot of energy is involved (big motor drives, etc). There may even be applicable safety standards, considering that flashes are often used right next to the head. Many standards (eg UL) place restrictions on failure-safety. At my last job, we had to rig our products up to deliberately cause failures so the certification engineers could check that the product would remain electrically safe during and after the failure. > I will "kill" it now before it tries again :-) Sounds like it's aready dead :) - Dave -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
