H750 (PDP-11) power on?

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Thu May 27 00:12:02 2004

>
> > Oh, check all the circuit breakers are on.
> > It's easy to knock on to the 'off' postiion.
>
> I don't see a big flipswitch circuit breaker on this old guy, nothing
> like the newer 11/34 that's here. There is a little 10A pushbutton,
> which has been depressed lately, but that's another story. <g>.

What about the breaker on the power controller?

And is this the 5.25" or 10.5" high CPU box?

>
> > ...there are 2 microswitches for the power switching function (and
> > one for the panel-lock function to disable the toggle switches). One
> > directly switches mains to the CPU power supply.
>
> This is a keyswitch front panel, with no key, so I opened it to the
> microswitches and tried pushing them to get the fans going, etc.
> and nothing. I judged, given the camming, that the lower switch
> (black,blue) was the panel unlock and the upper (grey,grey) the
> power. That might be incorrect. Also, the backpanel three pin
> connector described earlier came cabled, hence the suspicion
> that it was the/part of the power on. I'll try again tomorrow.

        
On the power controller there should be a little toggle switch. This
should be set to 'Remote'.

Try connecting the CPU mains cable directly to the mains (without the
power controller) and frobbing the microswitches (take care, at least on
the 5.25" box, one of the switches carries mains. Does that get it going?

-tony
Received on Thu May 27 2004 - 00:12:02 BST