[Info-vax] Old junk breaks

[Scott Dorsey]

Dave Froble  <davef at tsoft-inc.com> wrote:
>Well, my last working DEChub 90 power supply is no longer working.  It only 
>allowed for a terminal server, but, that can be useful.
>
>Anybody know what to look for to fix some of these units?

How did it fail?  Flashing lights?  Or worked fine, but then when turned off
it refused to turn on again?

Most of what goes wrong with supplies of that era are electrolytic caps, and
I am inclined to just replace them all with modern 105C types before even
starting to do diagnosis because leaky capacitors can make diagnosing other
problems more difficult.  As long as the transformer windings aren't open
and the power transistor isn't shorted, it's likely not hard to diagnose.
If the power transistor is shorted there will be a lot of collateral damage
to track down.
--scott

-- 
"C'est un Nagra. C'est suisse, et tres, tres precis."