This is a great newsgroup! The FAQ's and other info are most
enlightening, but unfortunately haven't helped me solve my problem.

I have an external firewire/usb drive enclosure that has bit the dust.
It's a pretty decent case - large enough for CD/DVD drives and with an
external 110V cord and internal switching 12V/5V power supply. I'd like
to salvage it if I can.

I've isolated the problem to the power supply, which just won't provide
enough current to spin up the drive (even though it shows 12V & 5V on
the connecter - albeit unloaded). If I power the drive from an ATX power
supply and let the internal PS power the Oxford IDE-Firewire circuit
board it works like a charm.

I've tried locating a replacement, without much luck. the PS is about 2
by 2 by 8 inches - very long and narrow. My first choice would be a
cheap ( $25) replacement if anyone can guide me to a source.

Another thought I had is whether I can modify an external 12V power
adapter to replace it, with a modification to drop the voltage to
provide 5V in addition to the 12V. From my weak memory of high school
electronics class, it seems only a resistor would be needed to step down
the voltage. I'm guessing it isn't that simple, since a newer drive
enclosure I own that uses an external adapter seems to require a number
of components to massage the power coming from the brick before it gets
routed to the hard drive.

Again, unless modifying an external adapter isn't very difficult, it
would probably be best for this neophyte to just replace the PS. If
anyone can suggest where I might find a small, not too pricey
replacement, I'd be much obliged!

Thanks!

Depending on how much current the drive needs
@ 5, & 12 volts, you MAY be able to use two
A.C., to D.C. adaptors, or use a 5 volt regulator
driven by one 12 volt A.C., to D.C. adaptor. Like
the one shown below. Sky.

http://cva.stanford.edu/cs99s/datasheets/LM340.pdf