Flash for camera quit working.

[Welchs101]

hi,

My dads flash for his camer quit working. I opened it up and found what looks to be either a bjt or mosfet in a radial can with some "junk" on the top of it. So i am guessing this is the problem part.

Problem is i need to find this part on-line and i am having troouble doing so. Can anyone identify this part for me?

see enclosed pics

[Welchs101]

Re: Flash for camera quit working.

anyone know? Should i post this in another section? If no responses then i will post in a section that i usually post in.

[kikkoman]

Re: Flash for camera quit working.

that's a 2SB324 Germanium transistor ( PNP, 32V, 1A, 0,22W).
they're not produced anymore and the proposed replacements are neither, but there are a few (NOS) on eBay for a few bucks.

[Welchs101]

Re: Flash for camera quit working.

what is NOS? Any idea what to search on in ebay?

[Krankshaft]

Re: Flash for camera quit working.

Guessing? Did you measure it with the diode check function to see if it's open or shorted?

NOS means New Old Stock.

[Jack Crow]

Re: Flash for camera quit working.

W101
That is a golden oldie. About 30 years minimum?

Something to try.
When electronics get that old, oxygen takes it's toll.
Dump the caps. Those things can hold 300 volts at a good amount of current.

Measure the resistors and see if they are still in 'spec'. Bet a number of them have drifted.

Also clean the heck out of the circuit boards. Use a good grade of Isopropyl Alcohol. You want them clean enough that there is zero visible contamination on the board. I use a cut down paint brush and old paper towels to soak up the gunk that comes off the boards. You will be amazed how much stuff comes off the boards.

What happens is that old flux tends to get conductive over the years changing the constants of the circuit.

Clean the board and measure the resistors again.
Remove and replace any that are no longer in spec.
Old resistors react with oxygen and drift in value.

Please do what Krankshaft said.
Check the transistors.
Since they are old tech Germanium, if memory is any good, they will read different than silicon transistors. But exhibit the same 'diode' type junctions. Expect leakage to be higher as well.

As for the 'brown gunk' on the two switching transistors.
In the day these things were made, using glue was the easy way to mount parts. In the photo you sent, glue was used to make sure the heat sink was going to stay put on the two transistors.

That brown gunk / glue gets conductive as well.
It also chews up copper.
Might pay to remove the glue and inspect what is under it.

Products like this and consumer goods were not built for the ages. Five or seven years was service life, then it was time to 'get a new one'.
So when it was made, all this stuff was normal and nobody had problems with it. Now it's old and the parts are suffering.

Much luck.

Jack Crow in Virginia

[Welchs101]

Re: Flash for camera quit working.

I think measuring it is a great idea. Let me do that and post the results.

any idea which one is the base, emitter and collector.........does not seem to be marked.

[Jack Crow]

Re: Flash for camera quit working.

W101
Don't just measure the transistors.
That is a good place to start.
Let's say they are good, then what?

Something stopped up the works.

As for testing the transistors Im trying to remember what the arrow mark stands for.
Poke around with the meter set for diode test mode and see what you get.

B to E and B to C should show you good diode junctions.

Be sure to test the resistors and other parts.
Jack Crow

[Jack Crow]

Re: Flash for camera quit working.

Pin outs.
Give this a look.
http://www.radiomuseum.org/tubes/tube_2sb324.html
That page has the pin out.

These are PNP units. We don't run into them too often, expect numbers to be 'flipped' from the more normal NPN transistors.

In the past I changed a bunch of power transistors that ran servo motors on a Bridgport milling machine. It was built with old G type units and I used S type w/o any problem. If these are dead, you won't loose much by subbing in some S type transistors and seeing what happens. Flash units are cheap. Any ham fest or photo show has them by the bucket.

Be well
Jack Crow

[b700029]

Re: Flash for camera quit working.

NTE102A is an equivalent replacement for that transistor. Somewhat expensive though.

Datasheet: https://cdn.badcaps-static.com/pdfs/...0fcccd40d2.pdf

[Welchs101]

Re: Flash for camera quit working.

I made some measurements:

Red Lead on MM/Black lead on MM: Device 1 resistance measurements
Pin1-Pin2: 1.071Kohm
Pin1-Pin3: 0.71kohm
Pin2-Pin3: open


Black Lead on MM/Red lead on MM: Device 1 resistance measurements
Pin1-Pin2: open
Pin1-Pin3: open
Pin2-Pin3: 1.03kohm


Red Lead on MM/Black lead on MM: Device 1 diode measurements
Pin1-Pin2: 0.16V
Pin1-Pin3: open
Pin2-Pin3: open


Black Lead on MM/Red lead on MM: Device 1 diode measurements
Pin1-Pin2: open
Pin1-Pin3: open
Pin2-Pin3: 0.159volts



Red Lead on MM/Black lead on MM: Device 2 resistance measurements
Pin1-Pin2: 1.006Kohm
Pin1-Pin3: 0.495kohm
Pin2-Pin3: open


Black Lead on MM/Red lead on MM: Device 2 resistance measurements
Pin1-Pin2: open
Pin1-Pin3: open
Pin2-Pin3: 0.952kohm


Red Lead on MM/Black lead on MM: Device 2 diode measurements
Pin1-Pin2: 0.16Volts
Pin1-Pin3: 1.3volts
Pin2-Pin3: open


Black Lead on MM/Red lead on MM: Device 2 diode measurements
Pin1-Pin2: open
Pin1-Pin3: open
Pin2-Pin3: 0.156volts

[Jack Crow]

Re: Flash for camera quit working.

W101
A while back I put this up and exactly nobody said a thing about it.
This is just the tool for odd ball elderly transistors.

It's a cheap curve tracer and it works with a dual channel scope set for X/Y operation.

http://www.flickr.com/photos/9010884...7626109758650/

A valid junction will give you an L shape.
A short a vert line and an open will show a H line.

Pure resistance will give you a slant line.

With this home made tool you can figure out EBC and see just how good the junction is.

Some day I will have to post the photos of it in operation.
Jack Crow

[Welchs101]

Re: Flash for camera quit working.

i would love to see the photos..........thanks for the info.

[Welchs101]

Re: Flash for camera quit working.

just curious, do those measurement i made look ok or do they look like the device is "bad".

[Welchs101]

Re: Flash for camera quit working.

Let me ask a dumb question.

If i measure the filament resistance of the flash......what should it be?

Does anyone know? SHould it be a short or open? Or something in-between?

[kikkoman]

Re: Flash for camera quit working.

since it's a gas discharge tube, there is no resistance (at least not at your measurement voltage), it should read wide open.
they can go bad after many discharges, but that's not very probable in a photo flash.

about your measurements: looks like no.2 is busted. E-C should give an open reading in any case.
if you replace it with a standard PNP Si transistor, make sure it can handle the current.
also replace BOTH transistors; although they're not a complement pair, I wouldn't mix Ge and Si types.

[Welchs101]

Re: Flash for camera quit working.

Jack-crow and kikkoman,

Thanks for all your help.

I will ask my dad if he wants to just buy a new one or wants me to spend money for parts. I guess originally we were both hoping it was just a cap or something simple......but turns out it might not be with this part.

I had another question regarding this flash unit and equivalent parts.

Jack-crow u mentioned using "s-type"......what are these and where can i find them.

Also,i asked digikey for equivalent parts to the B324 and this is what they gave me. Would any of these work? Just trying not to spend a lot of money when i dont know 100% if replacing this part will fix the problem.



http://search.digikey.com/scripts/Dk...=497-7171-5-nd

http://search.digikey.com/scripts/Dk...name=ZTX550-ND

http://search.digikey.com/scripts/Dk...ame=ZTX790A-ND

http://search.digikey.com/scripts/Dk...=MPSW51AGOS-ND




is one of the above a good equivalent repalcement.

[b700029]

Re: Flash for camera quit working.

The complementary pair suggests they're the switching transistors of the push-pull boost converter. Trace the circuit and post a schematic, it doesn't look too complicated. At least with that, we can see whether substituting a pair of silicon transistors wouldn't cause any problems.

[Jack Crow]

Re: Flash for camera quit working.

Guys,
When I said 'S Type' I was talking about SILICON transistors.
The G is the old germeniam type. For switching applications the difference is not so different. Linear is a whole different kettle of fish.

Since the unit is on the edge of 'write off' try a pair of cheap silicon transistors from Radio Shack. PNP's can be had. Put the pins in the right pads on the circuit board, get the E, B, and C right. If all else is still good, it might just run.

Jack Crow

[kikkoman]

Re: Flash for camera quit working.

@ b700029:

his measurements implicate that they're not a complementary pair but just two PNPs.
so, welchs101, if you could check the marking on the second transistor, that would help.