[Drake] PS-7 Problem

[Glen Zook]

The "pop" was probably the fuse going.  That is
usually caused by one, or more, of the rectifier
diodes shorting out.  Those are usually shorted out by
an electrolytic capacitor going bad.

New electrolytic capacitors are relatively cheap these
days from sources like Mouser ( http://www.mouser.com
) as are replacement diodes.  You need to open up the
power supply and check out the various parts with an
ohm meter.  Frankly, I would just go ahead and replace
all of the electrolytics with new ones and replace all
of the diodes if one is "blown".  Diodes cost just a
few cents.  

The electrolytic capacitors are going to be much
smaller in physical size than the originals and are
going to be much "tighter" in tolerance (new ones are
+/- 20% whereas the originals are often -50% / +80%). 
You will find the new capacitors in the "modern"
values like 33 mfd, 47 mfd, etc. instead of the old 30
mfd, 50 mfd, etc.  However, due to the tolerances the
new ones are going to be much closer to value than the
originals.

Glen, K9STH


--- Kevin Gray <k8su at adelphia.net> wrote:

Drake PS-7 made a large pop and stopped working.
Wondering if anyone has experience with this power
supply. Not sure where to begin.  Didn't want to plug
it back in until I had an idea how to proceed. 


=====
Glen, K9STH

Web sites

http://home.comcast.net/~k9sth
http://home.comcast.net/~zcomco


		
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