> > Black -----------------+------ P1
> >                       /         |
> > Black ---------------+        ~230V
> >                                 |
> > Brown ------------------------ P2
> >
> > Blue ----------(open)
> >
> > Green/Yellow---(open)
>
> This looks Ok, except for the grounding (you really need this for
> safety!!) and you'll need the neutral if anything else is plugged into the
> power box other than the 300V power supply.  No reason that I cna see why
> it wouldn't work.

Is it possible that, by fiddling with the serial port, one of your terminal
cable touched a grounded piece of metal (or is your laptop grounded ?)
Generally, big critters like that needs to be grounded, because they have
high current leaks (I can see little electric arcs when I plug a thin
ethernet
on my ungrounded Sun 3/260), and your cabling is "very floating" (no
neutral).
Maybe a leaked current has fried something around the PSU control logic ?
(seems improbable, but who knows?)

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