🚀 go-pugleaf

In article <1992Apr17.183517.11886@hubcap.clemson.edu> raghutp@hubcap.clemson.edu (Raghu Toppur) writes:
>There are no schematics available, and the Technical Assistance number is
>defunct. The problem is "obviously" :) in what seems to be a really fancy
>power supply board. There is one part here on the 115V side,
>which I have no idea what it is. 
>
>It sort of looks like a small SilverOxide battery which has been dipped in 
>tar, and has two leads emanating from it. Says CAL-R 2SS40 on it...

This is probably a MOV (Metal Oxide Varistor) if it is in parallel with
the power line, or a NTC (negative temperature coefficient) resistor, if
it is in series.  It's probably the latter; these have high resistance
when cold and low resistance when hot.  They are used to limit the surge
current when you turn on the power supply when the input capacitors are
not charged.  When the system is running, the NTC is hot and presents
very little resistance to the circuit.

The Digi-key catalog lists both NTC resistors (Keystone) and MOVs.

I suspect it would be much, much easier to replace the power supply
than to fix it.  If it is blowing 5A fuses look at the input bridge,
main capacitors, and main switching transistors.  However, some 3rd
component may have failed and you could waste a lot of time and
transistors looking for it.

	regards,
	geoff steckel (gwes@wjh12.harvard.EDU)
			(...!husc6!wjh12!omnivore!gws)
Disclaimer: I am not affiliated with Sun Microsystems, despite the From: line.
This posting is entirely the author's responsibility.