"Phil Allison" wrote in message
...
Arfa Daily wrote:


Today, having pulled all of the cabling out of the way, It was possible
to
see where the secondary wires spaded onto the lower PCB, and there was
just
enough room between the board stack and the cabinet side to mark them,
and
pull them with a pair of long-nose pliers. I then shorted the blown-out
thermistor, and hooked up the variac again. Same as before. 20 volts of
input, and the variac is grunting fit to bust, so it does look like the
transformer primary is shorted turns, as that's now the only thing
connected.


** Just as I suspected, those NRE toroidals are time bombs.


So now a case of seeing if we can get the tranny and inrush
thermistor, and more to the point, at what price ...


** Farnell have some 240V rated PTC thermistors that might do the job:

http://uk.farnell.com/epcos/b59810c0...65?ost=9753265

Check the one on the other tranny to see what cold resistance value you
need, probably something around 4 ohms.



... Phil


It's inside a piece of heatshrink sleeve bigger than I've got to replace it
with, but on the blown out one, you can still read "4R7" so I guess 4.7 ohms
which would be about right. Assuming that they have it done, I suppose I
will have to get a length of suitable heatshrink in so that it's restored to
the insulation levels that it came out of the factory with. I was able to
just about get my meter across the bridges after the tranny wires had been
pulled, just to make sure that there were no issues with them or anything
south of them, but all looks ok, so I think that it is just the tranny
primary short circuit for no good reason other than it felt like it ...

Arfa