[sdiy] juno 60 death

[WeAreAs1 at aol.com]

In a message dated 5/9/04 9:54:55 PM, zifcak at hotmail.com writes:

<< ok,
i measured correctly this time, and i'm getting 0 volts ac at the outputs of 
the transformer. i am getting 120 volts going in, so i'm pretty sure the 
problem is the transformer itself. nothing looks burnt though. it seems like 
all the blown transformers i've see show some sign of damage. could anything 
else possibly be causing this? strangely, i read a small amount of voltage 
*between* the windings. also, the voltage regulators seem to show a small 
voltage present (?). if it is the transformer, are replacements available 
anywhere? is the combination of 18vac center tapped plus 8vac common at all? 
thanks for any suggestions. >>

First, make sure you have thoroughly tested the Juno's fuse.  Just looking at 
it is probably not a good enough test.  You should remove it and test its 
resistance with your meter.  It should read very low resistance, near zero Ohms.

If the fuse is definitely good, then it really sounds to me like you may have 
a blown primary coil on that transformer.  Assuming that you do have 
multimeter, here's how to check:  Unplug the unit from the wall.  Put your meter in 
Ohms mode (resistance).  Put your meter's two test leads on the two prongs of 
the Juno's AC cord (on the two flat prongs -- not on the round ground pin).  
This will give you a direct check of the resistance of the primary coil of the 
power transformer.  If you get infinite or very high resistance, then your 
primary coil is blown.  If you get a low resistance reading (probably in the 
hundreds of Ohms range), then the primary is OK, and your problem lies elsewhere.

BTW, primary coils rarely burn out for no reason.  If the primary is blown, 
it would be a good idea to have someone with a lot of tech savvy check out the 
machine, or you may end up blowing your replacement transformer later.  It's 
for cases like this that an AC Variac with an amperage meter comes in very 
handy!

Good luck,
Michael Bacich