no, Here is how it went

what happened was all the lights in the house dimmed and it blew the fuse, I
think there was a direct short on the supply rail, especially when it blew
an 8 amp fuse.


now, there are 8 transistors, 4 per channel. every one of them have the same
marking. I know they are NPNs, I can tell by the circuit connections. Amps
are simple to me. I fix every one I run into. But, I always come here first
to get cross, or some pointers.

anyway, i pulled out every transistor, and from BtoC and BtoE reads around
..4xx on all of them, and on one of them I get .2xx both ways.

Now, here comes the tricky part. I thought all of the transistors were good,
when I read those readings.

I checked A side, and the CtoE read oL both ways, (open lead). so, thats
normal. now, on the other side, 3 of them read oL, and one of them, read
..000(short), both ways.

and that there, would ground out the supply rail, which is what is
happeneing.

and usually, when you read BtoC, or BtoE, the readings are slightly
different from each other right?

well, on the shorted one, from BtoC, and BtoE, are the same readings,
indicating CtoE short.



"Marko" wrote in message
...
Mike: Assuming that you are using a diode checker to check the junctions,
if you get a junction from CtoB and BtoE then it is good. You can't go to
E
from C without going thru B. If it is a standard bipolar transistor.
Sounds like you may have a darlington which can have strange readings,
especially if there are internal resistors. Do you get the voltage drop
across the junctions in only one direction? If it is a simple BJT
(bipolar
trans) then it should block in the reverse direction. Darlingtons, which
have two transistors combined for extra gain, can give all sorts of
readings.

If all eight read the same I would look elsewhere in the circuit before
buying a bunch of transistors. MH (top post)
"Mike" wrote in message
...
I have a peavy amp Mark V series from the 70s, and
each channel has 4 output transistors in the TO-20 or something like
that
packedge,

its got the circle in the middle, and two leads comming out of the back,
B
and E, and the case is C with 2 screw holes in it.

Well, I need a cross, its an RCA transistor, and it shorted. I cant find
that part number in MCM, or my datasheet site.

it says RCA, and under it says C8645, im guessing its 2SC8645? but
nothing
comes up.

Above RCA, it has the serial, labled 67376-C

Any Ideas? I need 8, I might as well change all of them out preventing
this
from happening in the near future. its very old amp, but it will blow
the
roof off

one day, I turned it on, all the lights in the house dimmed, and blew
the
fuse. again, and again.

And found 1 out of the 4 for B side shorted. I might as well change all
4,
and change the other 4 that are good just in case. you never know.

Anyway, I checked the rectifiers, and checked bias resistors, and other
resistors and so forth for aging, and drifting in value do to age, and
found
none.

it just shorted between C and E, but I can get good readings from C to
B,
and B to E, with about .465 for each, but .000 on C to E, indicates
short,
I
should have no reading here. or oL