On 03/01/2011 14:00, John wrote:
I have just dug out my old Vivitar 2500 Flash to try with my Canon Powershot
SX10IS.

It was working and I was getting used to it and then it failed. Tried fresh
batteries and it is erratic. I hear it whining as it charges but the ready
light isn't coming on. If I press the manual button I can see a faint
flicker in the flash tube and the green light flickers.

Has anyone got any ideas about how these fail?


The first thing to try is replace the large capacitor. If left for a
long time electrolytic capacitors begin to leak (electricity that is)
which would explain the symptoms you have. They're cheap so it's worth a
shot.

Another Dave