Reviving old flashes
I remember reading an article outlining a generally safe procedure for easing a long dormant flash back into life so as to not fry the capacitor right from the start. I think it was on Strobist, but I completely went through the article index and couldn't find it. Google searches were equally unhelpful.
If someone has either a link to a good article or has experiance with an idea of how to handle this that would be a great help.
Thanx in advance.
I think a lot of that talk is nonsense.Not entirely though. I'd say to put some older batteries in it and run it a little, let it sit, run it some more, and repeat several times till one time when you see the ready light, and turn it off to sit. It ought to work out OK. If the capacitor is that weak, may as well find out now.
Some years ago I looked into fixing a beloved flash unit. The problem I encountered was trying to get a capacitor that would fit in the space of the old one. The ones that would work electronically would not fit geometrically. I came to the conclusion that it was just not worth the trouble.
BTW, even the charge in a weakened capacitor can be very dangerous. All the is necessary to stop your heart is a few milliamperes of current propertly delivered.
You are referring to a method of "reforming" the dielectric of old electrolytic flash capacitors.
The method has merit but in the case of old flashes, might not be worth the trouble.
I have lots of old flashes going back 35 years, so far never a failure.
The old flashes have little value, pulling them apart is no fun and it is likely to result
in consequential damage like broken wires ( or worse a fracture that does not quite break till later)
or lost parts.
If you want to treat a capacitor gently, use a partially discharged set of batteries initially,
"blip" the on switch - off and wait a few minutes, repeat over an hour or so till the neon is on.
I never bothered to do this, but i do run all my old flashes every 3 months or so.
My main concern is I am acquiring a Leica with a leitz/braun flash. It isn't very old age wise, but probably hsnt been used in years. I don't want to just fry it right from the start so looking for more of a soft start routine just to play it safe.
I really have no intention of opening the flash to start off, I'm not comfortable enough with safe handling of caps, but just want to try the option of a safe start.
I appreciate the responses guys! I will try with an old but not dead set of cells to start and ramping up the time on the cap for a while.
A camera flash that isn't going to have enough amperage to kill you, but it can bite pretty hard (been there). If you get shocked by it, you might swear off working on it again - and you will probably swear.
It is easy to short a cap to discharge it, and then you will be safe.
The worse part would be trying to de-solder the capacitor, then solder a new one in, without damaging the unit with the soldering iron. I've not fixed a flash, but there is not a lot of room to work with.
That said, I'd just load some batteries like you intend. There is a good chance the unit will be fine.
No, any of the higher energy capacitors should only be discharged though an adequately rated resistor
Originally Posted by Truzi
Both to protect the operator, and the capacitor's life.
For an average flash capacitor, let me say a 10,000Ohm 20 Watt resistor , or similar, commonly available eg at radio shack
with insulated leads, let it remain connected directly across the capacitor till dc voltage is less than 12 V, and wait 1 minute longer.
I was going to mention a resistor, but would have been too tempted to go down the path of the resistance of human skin, etc.
Good to know ^^ but, again, I have no intentions of opening it up. I have plenty of other flashes I could use, but I just hate to potentially ruin a flash by throwing new batteries in there and just firing away.
Other flashes I have that were purchased after 4-5 years of non use have always fared fine, but there's a good chance this one hasn't been used since the late 90's.
New batteries aren't likely to hurt the flash - as in damaging it where old batteries wouldn't.
They are just unlikely to help it if you are trying to nurse it back to operation.
I would have different advice if you were talking about a flash that uses a high voltage, over the shoulder battery pack.