Need Help Identifying B936T

I released the magic smoke from a camera flash unit (Vivitar 285HV) and tracked it down to a single part. It is marked only with B936, T, and 50. I can't for the life of me find what it is. No schematics, parts lists, etc.

As shown, the right lead receives +6V, while the center and left pins go to a small transformer.

I would very much appreciate any assistance in determining a replacement.

That would be a 2SB936. It's PNP power transistor. You'll find datasheets & cross-reference guides on the net.
Beware when you buy it that you don't get a surface mount version.

I can't seem to find a suitable replacement. Mouser, Digi-Key, and Maxim all seem to strike out.


http://www.datasheetcatalog.org/data...JD00017BED.pdf

Try to look for 2SB896 and see if it's easier available, it should have comparable data.

Thank you very much. I ended up ordering several NTE378 transistors as they cross-referenced rather closely to the 2SB896. Hopefully it all plays nicely.

Ok, hope it works out, never easy to tell with such self-oscillating circuits, just have to try.
The NTE seems a tad slower than the original, while the 896 seemed a tad faster but it might not matter.
Depending on the room in the flash you might have to cut the tab and trim the width of the legs to make it fit.
Use a hacksaw for the tab, fixing it by the very end in a vise to avoid stresses on the chip.

I found some D45H8 transistors at a local shop that are NTE378 equivalents, however the flash fails to function, so it's hard to decide if there's something else fried, or if the transistor's not appropriate.

The heatsink tab on the transistor gets very warm with power applied for only a second or two, and it clearly draws a good bit of power based on the spark at the battery terminal :-P

We have a FIX!!!


Silly me...I was applying power based on a big + and - on the circuit board, however they do not correspond correctly to the battery compartment. The flash works like a charm.

Thank you again for your assistance...forums are the best!



EDIT:

The transistors work, but they get VERY hot and one fried after very little usage. Is it likely to be another blown component, or is it more likely that the transistor is slightly out of spec?

There may of course be a reason the original transistor fried, and it may still remain.
Determining what it is can be difficult, especially if there is a short in the transformer.
I tried a replacement transistor in a 12V fluorescent light once (it works on the same principle as a flash) and the same thing happened. I never got around to investigating the source of the problem though.
I'm not quite sure how to guide you to find the fault, and it may take some measuring equipment.
If you can post a picture of the component side of the PCB I could have a look and see if I come up with any ideas.
And if you are able to fit a piece of aluminum to the transistor it may live longer, but battery life will of course still suffer.