help!
you seem to be right in having broken the fuse, and it _is_ a little
green thing, looking like a resistor, but it's a fuse anyway, and has
to be soldered into the motherboard. I got the same mouse failure
some time ago when I plugged in a dongle for a CAD prog, and had to
change the fuse. If you want to first check if it has blown, meter
if there is still +5 V power on pin 7 of the mouse connectors.
The fuse is located next to the mouse ports and near U202. I dont't
know, if this will be F1 (not all revs of motherboards will have this
little green fuses, and in the schematics I obtain, they aren't
included).
I just wonder if you _really_ got a resistor in the place of F1.
Maybe your dealer put it in when repairing it in warranty some years
ago, as you mentioned. These little green fuses are _very_ hard to
get as spare (at least here in Germany) and they are expensive (I
paid about $10 for one of these little thingies). I'm just imagining
your dealer might have put in a resistor with low resistance on
repair instead… 🙂