Apple power supply problems - test-drb@ccmp.vtda.org

8 Oct 1998

One method that I have used for years with equipment that blows fuses is to
put a light bulb in line with the incoming power.  Depending on the actual
correct load of the equipment determines the wattage of the bulb needed.  On
normal operation the bulb will light to about 1/4 to 1/2 of normal then dim.
(typical inrush - charging caps.)  If the bulb lights near fully it is
taking the load instead of blowing the fuse.  At this time you can use a
meter and find the defective component.  Usual caution applies the equipment
is floating if the bulb is in line with neutral.
Dan Burrows
dburrows(a)netpath.net

-----Original Message-----
From: John Foust &lt;jfoust(a)threedee.com&gt;
To: Discussion re-collecting of classic computers
&lt;classiccmp(a)u.washington.edu&gt;
Date: Thursday, October 08, 1998 12:30 PM
Subject: Re: Apple power supply problems

...
 At 08:34 AM 10/8/98 -0700, Marvin wrote:
  Running it a short time with
the fuse shorted out heated up the chip and I was able to feel where the
problem was.  Troubleshooting vs normal operation :). 
And sometimes when you do that, the dead chips will notify you
of their new condition by blowing their tops.

- John 