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Peabody[_4_] Peabody[_4_] is offline
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Default Vivitar 3500 "zoom thyristor" flash won't whine

abrsvc says...

Someone on the EEVblog forum says the part number is
actually 2SB324, which is a germanium PNP transistor.
I'd guess I won't find a direct replacement for that.


NTE still sells crosses for stuff like that. Looks like
NTE102A. Must be old stock. I doubt the chinese would
even fake those.


OP may provide details, but I supplied transistors to
him and as of this writing, one is working by changing
transistor and some caps.


Yes, thanks very much, Dan. I found that one of the two
ganged transistors had failed short. So I replaced that one
with one of Dan's 2SB324 transistors, and I replaced the two
electrolytic capacitors, one of which tested bad for ESR.
And now it works.

I have two more of these flashes which still work, but don't
always spin up when I first turn on power. I'm going to
make sure their transistors are good, but I'm going to
replace their capacitors. The existing ones are 35 years
old, so it's not too soon to replace them. They are
Panasonic CE series, which don't appear to have been
anything special.

Thanks for bailing me out, Dan. I was thinking of trying to
switch over to silicon transistors, but at least for now I
don't have to do that. These flashes run on two NiMH AAs,
so about 2.4V, so the lower base drop of germanium may
actually be important. Anyway, I was not looking forward to
making that transition.