11 Mar
2010
11 Mar
'10
6:31 p.m.
On 11 Mar 2010 at 10:07, Zane H. Healy wrote:
I will get the XP1000 working again soon, but only so
I can recover
data off of it. From now on it will only be powered on when I need
it. :-(
I was working over a 4U rackmount industrial PC that had an ATX PSU
in it. This had a supposedly "hard" power-off rocker switch and the
PSU even has an IEC socket on it for powering other equipment, such
as a monitor. So, I figured that the power switch was a real one,
that disconnected the PSU from the AC line.
Imagine my surprise when I put my hand on the PSU case that had been
powered off for two days and found it to be warm. It turns out that,
just like the 'soft-power" ATX supplies, it keeps a small DC voltage
on continuously. The secondary power outlet is switched by means of
a relay.
Fortunately, the thing usually is plugged into an IEC power strip
that's controlled from a master switch on the rack, so it normally
doesn't matter. I had the unit out on the bench and plugged in for
testing.
I really miss the BRS on PCs, when "off" really meant "off".
--Chuck