[Info-vax] Used DS-10 or equivalent recommendations?

[Scott Dorsey]

Chris  <xxx.syseng.yyy at gfsys.co.uk> wrote:
>If the fans are running, check if they are dc, typically 12 volt input.
>Also, the user or service guide might tell you what the led pattern
>on the motherboard is telling you in terms of the  the power on
>self test failure.

Correct, and I will confirm that the fans do run on the 12V rail.

>If the fans are dc and  running, it probably means that the psu is
>at least partially ok, as all the psu rails come from the same
>converter typically, with only the 5 volt rail sensed for regulation.
>Use a voltmeter to check values at the motherboard power connector.

I will confirm all of these things, although the standby power does not
come from the same converter and it is the first thing I would suspect.

Also, although they all share a transformer, the output filter networks
on each are different, and it is possible for one rail to be noisy or
sagging while others are fine.

>Doesn't do any harm to change all the caps though, if you can get at
>them without stripping the whole psu down. Not usually for the
>faint hearted though :-)...

The DS-10 supply isn't too bad in this regard.  They don't sneak caps
under heatsinks where they will bake out and where removing the heatsink
is needed to replace them.  They don't use caps that vomit out corrosive
material that etches out board traces like the Apollo machines....
--scott


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