testing com ports

[M00CH]

is there any way to test a com port without having anything attached to it...

i have a mouse that i think is dead but im not sure, or it could be the com port dead, again not sure. can i test the port with a volt meter to see if it getting power...

need help

[A380]

if you test this, you'll only know if you get power. but it doesn't tell you if all the wires are ok(speaking about the internal ones)
so you should connect your mouse to a com port of which you know it works.
A380

[Tecumseh]

Most PC's have two com ports. Get at null modem cable and
connect them together. Then start hyperterm on each one.
If stuff typed in one shows up in the other and vice versa, then
you can be pretty sure all is well.