22 Feb
2009
22 Feb
'09
8:11 a.m.
--- On Sun, 2/22/09, js at cimmeri.com <js at cimmeri.com> wrote:
After removing all the boards and leaving just the disk and
tape drive for
load I impetuously decided to try powering it up. I knew
the PSU (model
H7864) was set for 110V and made the switch to 240V (I am
in the UK). When I
connected the power cord, after a few moments there was a
loud pop, followed
by another before I could pull out the power cord, smoke
rose from the PSU.
This sounded just like when I had once accidentally made a
110/240 mix-up.
The question is, could it be that I had not made the switch
to 240
correctly, or could this just be down to the age of the
PSU?
Could be. What cabinet is this in? A BA123? Those have two power supplies. One for the
disks and half the cards in the backplane, the other for the other half of the backplane,
and perhaps fans. I forget the distribution. But when you remove the power supply,
you'll see that there are two seperate boards there.
You may very well have blown up one because of improper voltage - or perhaps you
didn't have it loaded enough. Old switchmode supplies need a load in order to work
properly. Normally, they just don't output voltage, but I've seen them burn up
before.
-Ian