[Rack] problems in Susan the Rack: two machines died
jim at well.com
Sat Feb 27 12:00:24 PST 2010
i had two 1U computers running in Susan the Rack.
yesterday (Friday 20100226) i discovered neither
was working--neither would power up.
i discovered that both were plugged into the back
of the UPS, where i'd left them not plugged in (to
save power: 100 to 200 Watts 24/7 as opposed to a
few hours each week when the linux sysadm study group
meets). also, there's a new dent in the back of one
of the boxes.
i removed one, took it apart, and dissected the
power supply. line power appears at the plug at the
back and on the connections on the PC board, but
power is not distributed throughout the sub-systems,
all pins in the molex connectors were dead.
i'm guessing this is the state of the other 1U,
as both show the same symptoms.
the coincidence is suspicious: two machines both
working and then both not working and with the same
symptoms. there are two commonalities. some person
has definitely dicked with the two boxes, if only
to power them up, perhaps to have moved them or
dropped them.... also, both were plugged into the
back of the UPS. Both seem to have suffered the same
Did someone drop both? Did someone make some
connection that presented overvoltage (or a hot
ground...)? Did the UPS hiccup or otherwise
misbehave and fry some component in each of the
two power supplies?
if you have an idea as to what happened to both
of my 1U boxes, please let me know: i'm unemployed,
have little money, have spent a lot more money than
i'd planned on noisebridge stuff, and now have to
spend more money to repair these boxes. knowing
what happened will help me diagnose and defend
against future such calamity and possibly spare me
some future expenses.
i note also that the wiring in the back of the
rack is a mess, worse than most i've seen in the
backs of racks. i will likely try to dress the
wires somehow. i ask that anyone working on the
rack remember to be excellent to others working on
the rack and adhere to standard practices in wiring
and fastening and power and bandwidth
415 823 4590 my cellphone, call anytime
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