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?

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

"John" wrote in message
...
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?



Marked as 380 micro farads 350v "for Photo Flash"

40mm long by 25mm diam.

I guess it dates from about 1980

On Mon, 3 Jan 2011 14:00:38 -0000, "John"
wrote:

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?

Possibly just slightly corroded battery contacts - so try cleaning
those first. More usually though it is the large high voltage
electrolytic capacitor which acts as the tubes energy store develops a
leak (partial short circuit). If unused for years it needs
"reforming" before being put back into use.

Replacing them isn't too difficult if you can solder but beware - even
a leaky capacitor of that voltage (about 300VDC) and size (about
800uF) can administer a very large shock so ensure everything is
discharged before playing with it.

Finding a replacement of the right dimensions and characteristics may
not be simple. Normal electrolytic capacitors don't survive the
rather brutal regime of a flash gun too well and a photoflash rated
capacitor may be difficult to find. That said if you don't use it too
much a standard capacitor will work - it just won't have a very long
life.

There are some Vivitar 2000 series photos at
http://www.pixcontroller.com/forums/...?showtopic=336
which will give you some idea of the layout.

By the way - be careful using old flashguns on modern cameras. Many
cameras flash trigger circuits on the top hotshoe are only safe at low
voltage (5V or so) and some old flashguns can have several hundred
volts on the trigger connector.

The Vivitar 2500 has about 12V on the shoe so is a bit iffy.

http://www.botzilla.com/photo/strobeVolts.html

"John" wrote in message
...
"John" wrote in message
...
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?



Marked as 380 micro farads 350v "for Photo Flash"

40mm long by 25mm diam.

I guess it dates from about 1980



Crikey - I just touched an insulated screwdriver across the terminals - hell
of a flash and bang. Glad it was insulated.

Nothing has changed (except my screwdriver has burn marks.) Glad I knew
enough to be careful whilst being reckless!

John wrote on 03/01/2011 :
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 capacitor is the most likely to have failed - often happens to long
disused electronics.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"Peter Parry" wrote in message
...
On Mon, 3 Jan 2011 14:00:38 -0000, "John"
wrote:

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?

Possibly just slightly corroded battery contacts - so try cleaning
those first. More usually though it is the large high voltage
electrolytic capacitor which acts as the tubes energy store develops a
leak (partial short circuit). If unused for years it needs
"reforming" before being put back into use.

Replacing them isn't too difficult if you can solder but beware - even
a leaky capacitor of that voltage (about 300VDC) and size (about
800uF) can administer a very large shock so ensure everything is
discharged before playing with it.

Finding a replacement of the right dimensions and characteristics may
not be simple. Normal electrolytic capacitors don't survive the
rather brutal regime of a flash gun too well and a photoflash rated
capacitor may be difficult to find. That said if you don't use it too
much a standard capacitor will work - it just won't have a very long
life.

There are some Vivitar 2000 series photos at
http://www.pixcontroller.com/forums/...?showtopic=336
which will give you some idea of the layout.

By the way - be careful using old flashguns on modern cameras. Many
cameras flash trigger circuits on the top hotshoe are only safe at low
voltage (5V or so) and some old flashguns can have several hundred
volts on the trigger connector.

The Vivitar 2500 has about 12V on the shoe so is a bit iffy.

http://www.botzilla.com/photo/strobeVolts.html






As my need was somewhat speculative then I think I will avoid any risk to
the camera and forget about the flashgun. I got a few useless pictures of my
study whilst it was working - so it had no immediate damaging effect on the
camera. Not worth the risk though - and it looks like getting a new
capacitor may be difficult.

At least I took it apart and had a look inside.

In article ,
says...
Crikey - I just touched an insulated screwdriver across the terminals - hell
of a flash and bang. Glad it was insulated.

Nothing has changed (except my screwdriver has burn marks.) Glad I knew
enough to be careful whilst being reckless!


q.v. thread about microwave lamp!

--
Skipweasel - never knowingly understood.

On Jan 3, 2:00*pm, "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?

TBH I was initially surprised you hadn't blown the crap out of the
Canon, as I thought the 2500 was old enough to have it's full flash
voltage across the trigger terminals; but Google suggests it's around
13-14V for the 2500 so presumably that's within the Canon's limits.

"airsmoothed" wrote in message
...
On Jan 3, 2:00 pm, "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?

TBH I was initially surprised you hadn't blown the crap out of the
Canon, as I thought the 2500 was old enough to have it's full flash
voltage across the trigger terminals; but Google suggests it's around
13-14V for the 2500 so presumably that's within the Canon's limits.


I looked through the manual but couldn't find any limits. I will steer clear
though. I had it in mind for a once a year large group photo. I'll forget to
take my camera and let someone else do it!

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?



I _am_ guessing, but I'd go for an HT leak somewhere. Take all the
covers off and run it in the dark and look for sparks. Could be leaky
capacitors.

Andy