Courtenay Solaflash 8000 capacitors blown

[Philip Taylor]

I was trying to find the return voltage on my old Courtenay and popped it too many times (double charged I guess). Two big "pops" and smoke rising.

So, the question is, does this sound like a simple replacement of capacitors or far more expensive repair?

 

[Mike Wilde]

Old gear - if you did not leave it powered up for 20 minutes or so without popping it, it probably would not have failed. Electrolytic capacitors depend on their use of a thin film that forms when they are under powered conditions, and gradually dissolves when they are not powered up for quite a while.

You may have had the blown cap spray bits of molten innards onto other components, causing them ill. Or you may have had an oscillator transistor or voltage doubler diode blow from over current.

The troubleshooting effort may outweigh the value of the flash pack.

The caps themselves are not impossible to swap out, but you do not sound like you are up to the task yourself, at first blush.

 

[Philip Taylor]

Yep, I've been using old flash gear for many years so know all the rules...this was just me struggling with a multimeter and stupidly forgetting its a BAD thing to re-fire it a bazillion times in a few seconds...

Anyway, yes, you're right - I'm pretty good with my soldering and know some basic electronics, but don't really consider myself savvy at fault finding with stuff like this.

I could possibly do the caps myself, but not keen to touch the rest.

 

[Johnkpap]

I had a cap go on a old Multiblitz 702 head I bought many years ago,
I paid like $50 for it as it had a broken power output knob. I replaced
the pot fired it up triggered it on low one or two times then triggered it a
full power --BANG-- one of the caps went. I had a hard time finding one
in the end I found one that fitted with the same spec in a junk shop.

The Multiblitz is still going strong afted many years of use.

Older flash heads are alot easyer than new ones to fix....alot less
electronics in them just take care around caps I always discharge them
with a big resistor 10watt (100k)

Just be aware that older flash camera trigger/sinc voltages can be quite HIGH
this voltage will fry a Dslr or AF camera

The best source of cheap replacements is your local flash repair person
they normaly have dead heads they will part out if you are nice.

Johnkpap

 

[Rudeofus]

I'm sure you have read Dead Link Removed in great detail, are fully aware of the high voltages you will encounter in a flash device and the dangers these bring about.

If you find out that indeed only a capacitor blew up inside, I recommend the following steps:

1. Make sure some time has passed since you had the flash powered up the last time.
2. Discharge all electrolytic capacitors and make double sure they are indeed discharged.
3. Clean up the mess inside as much as you can as soon as possible (caps must be discharged before!!! ). The goo that comes out of electrolytic capacitors is quite corrosive and will readily attack circuit boards and the like. Use whatever it takes to get it out.
4. Unsolder the defective capacitor. If it was just one of several caps that are in there, try to read the rating from the remaining ones.
5. Also try to find out reliably, where the plus end of the broken electrolytic capacitor went. If you mistakenly swap polarity with the new cap, it will blow up very quickly.
6. If there was really just one cap of many that you had to remove, try reassembling your flash device and see whether it works. There is a good chance it will fire, albeit at reduced power. If it still doesn't work, the electric circuitry is likely damaged, and it is up to you to decide whether you can repair it. Don't forget points 1. and 2. before you try this!
7. Assuming you now have a flash that fires at reduced power, or one that just doesn't have enough capacitors to flash, try to get a new capacitor with the correct rating. Caps with higher voltage rating are fine, but caps with much higher capacity will likely blow your xenon tube. Needless to say you shouldn't get caps with lower voltage rating or much lower capacity. Also try to get new caps and not ones from junk yards, remember you just had the pleasure of seeing what old caps do when they are suddenly charged. New caps will likely be much much smaller in geometry for the same electrical rating, which gives you more options with connecting them correctly - I have never seen replacement caps that would fit straight into the circuit board they were purchased for.
8. If you reassemble your flash, make sure there is enough distance and/or insulation between parts that carry high voltage. Account for the fact that shock and vibration can and will change these distances.

Good luck!

 

[Mike Wilde]

I am presently rehabillitating an old stareo receiver, feeding it a collection of new electrolytic capacitors.

I source a lot of stuff from Parts Connexion's e-site. They are pysically local to me, but actually seem to mostly deal with audio modify and repair folks all over the world.

In their bargain basement section of the e-store at the moment are some large capacitors of the sort found in studio flash for some very attractive prices.

I am mulling rpreemptively stocking up for the inevitable day that my old Speedotron studio flash spits out dead caps.

 

[Rudeofus]

It's a big pain and risk to open such a device, and having to do it once more just because someone tried to save a dime on capacitors seems to be a questionable path to big savings. Contrary to that, I'd recommend getting brand new long life electrolytic capacitors, and replacing all of them while you are at it. All these caps together should be profoundly cheaper than any decent studio flash.

 

[pasiasty]

2. Discharge all electrolytic capacitors and make double sure they are indeed discharged.

Don't do it by short-circuiting (e.g. a screwdriver or a piece of wire)! Rather for use a resistance that is able to absorb and emit the energy. A 50-150W light bulb (rated for 220-240V) is quite good for this, it will take some time (up to a minute) until full discharge.

 

[Mike Wilde]

Yes, I have a straight bladed screw driver with one corner of the blade melted away mounted above my work bench to remind me not to be stupid agian.

The example was caused by disassembleing a handle mount flash without letting it bleed off overnight with the battery out.


The thing sounded like a shotgun being discharged indoors when it blew the corner off of the screw driver.