20 Dec
2009
20 Dec
'09
10:50 a.m.
Tony Duell wrote:
Well, OK, if the Phantom (as the Radiophile magazine calls him) or that
well-know UK radio amateur M0RON has been in there before you then all
bets are off.
The DEC power cotnrollers are _very_ simple
inside, and you don't really
need tjhe printsets to repair them.
You need the print set of a DEC power control if you're trying to figure
out why the power control in a Type 30 point-plot display attached to a
PDP-1 keeps tripping its circuit breaker as soon as mains voltage is
applied to its input. Once you have the print set, it becomes apparent that someone seriously miswired the innards of the
power control,
possibly in a previous misguided repair attempt. Upon rewiring it to
factory spec, and replacing a switch on the front of the power control
that turned into a dead short when it was miswired, it will then work
properly.
However, I suspect in this case I could have got it doing the right
things without a printset. Not necessarily the original DEC circuit, but
at least not shorting out the mains.
-tony