hard disk apparently stops powersupply working

My computer failed to start and when I checked, there was a burning smell
from the powersupply so I naturally concluded that the powersupply had died.
I exchanged the powersupply (an ATX type) and still the machine did not
start, not even the fan in the powersupply was turning. I swapped my hard
disk for another and then the powersupply fan starts to turn. What could be
causing this? I can understand that the hard disk could be damaged, but how
could this be preventing the powersupply fan to turn?

"-keevill-" wrote in message
...
My computer failed to start and when I checked, there was a burning smell
from the powersupply so I naturally concluded that the powersupply had
died.
I exchanged the powersupply (an ATX type) and still the machine did not
start, not even the fan in the powersupply was turning. I swapped my hard
disk for another and then the powersupply fan starts to turn. What could
be
causing this? I can understand that the hard disk could be damaged, but
how
could this be preventing the powersupply fan to turn?

Not sure, but if it's any help, the exact same thing happened to my
computer. Mine was a Seagate hard disk.

Most likely the dead hard-drive is shorting out one of the supply rails on
the Power Supply, and the Short Circuit protection in the Power Supply is
preventing it from powering up....... Otherwise it would burn up too........
Expected behaviour............

John S.

"-keevill-" wrote in message
...
My computer failed to start and when I checked, there was a burning smell
from the powersupply so I naturally concluded that the powersupply had
died.
I exchanged the powersupply (an ATX type) and still the machine did not
start, not even the fan in the powersupply was turning. I swapped my hard
disk for another and then the powersupply fan starts to turn. What could
be
causing this? I can understand that the hard disk could be damaged, but
how
could this be preventing the powersupply fan to turn?

-keevill- wrote:
My computer failed to start and when I checked, there was a burning smell
from the powersupply so I naturally concluded that the powersupply had died.
I exchanged the powersupply (an ATX type) and still the machine did not
start, not even the fan in the powersupply was turning. I swapped my hard
disk for another and then the powersupply fan starts to turn. What could be
causing this? I can understand that the hard disk could be damaged, but how
could this be preventing the powersupply fan to turn?


short in the HDD, quite common. bin it and get another, or return under
warranty.

On Mon, 10 Nov 2003 14:23:34 +0700, "-keevill-"
wrote:

My computer failed to start and when I checked, there was a burning smell
from the powersupply so I naturally concluded that the powersupply had died.
I exchanged the powersupply (an ATX type) and still the machine did not
start, not even the fan in the powersupply was turning. I swapped my hard
disk for another and then the powersupply fan starts to turn. What could be
causing this? I can understand that the hard disk could be damaged, but how
could this be preventing the powersupply fan to turn?


A short on the hard drive would cause the PSU to shut down, they have
overcurrent limiting built in.

JT

-keevill- wrote:
My computer failed to start and when I checked, there was a burning
smell from the powersupply so I naturally concluded that the
powersupply had died. I exchanged the powersupply (an ATX type) and
still the machine did not start, not even the fan in the powersupply
was turning. I swapped my hard disk for another and then the
powersupply fan starts to turn. What could be causing this? I can
understand that the hard disk could be damaged, but how could this be
preventing the powersupply fan to turn?

a duff hard drive can stop the psu turning on, not sure exactly why, but
it's prob a safety thing
(for the pc's safety, not yours btw)

-keevill- wrote:

My computer failed to start and when I checked, there was a burning smell
from the powersupply so I naturally concluded that the powersupply had died.
I exchanged the powersupply (an ATX type) and still the machine did not
start, not even the fan in the powersupply was turning. I swapped my hard
disk for another and then the powersupply fan starts to turn. What could be
causing this? I can understand that the hard disk could be damaged, but how
could this be preventing the powersupply fan to turn?

A short in the +5v control circuitry in the HD will trigger the Isc
circuit in the PSU, shutting down the PSU.

Happens quite often.

Howdy!

"-keevill-" wrote in message
...
My computer failed to start and when I checked, there was a burning smell
from the powersupply so I naturally concluded that the powersupply had
died.
I exchanged the powersupply (an ATX type) and still the machine did not
start, not even the fan in the powersupply was turning. I swapped my hard
disk for another and then the powersupply fan starts to turn. What could
be
causing this? I can understand that the hard disk could be damaged, but
how
could this be preventing the powersupply fan to turn?

The overcurrent protection on the power supply, which is there to a)
avoid actually setting fire to the computer, and b) protect everything else.

Too much current, and presto! Power supply shuts down.

RwP