Dead FW ports

[Diannah Morgan]

Hi,

I've got some old G4-400's in a classroom and I believe I have dead FW ports
in some
of the machines.  Apple profiler can't find the devices.(Usually it says
"built-in")

I'm pretty handy inside a machine.  Is there a website that explains
swapping them out
for new components?  And where's a good place to get newones? (is it as
simple as
swapping out a modem for a stealth serial port?)

Or am I stuck getting new mother boards.