Testing Power Supplies! Re: Norsk Data Nord-10/S restoration effort on the way!

[Paul Koning]

>>>>> "Joe" == Joe R <rigdonj at cfl.rr.com> writes:

 Joe> Testing power supplies before powering up a system is just plain
 Joe> paranoid! (And I'm trying to be polite here!) There are a
 Joe> thousand parts in modern computers that can cause just as much
 Joe> damage!!!!!!!! 

I disagree -- at least in the case of linear regulator supplies, which
is what you'll normally find in a classic computer.

A very simple and very nasty failure in a linear regulator is a short
in the pass transistor.  If that happens, you get a much higher output
voltage, and there is no current limiting.  It's a fair bet that this
will fry a large fraction of the semiconductors in your system.

If the supply has a "crowbar overvoltage protection" circuit in it,
that's a different matter.  But testing a linear supply is trivial.
So why not do it?

If you let the magic smoke out of the  computer, it's too late...

   paul