I recently purchased a secondhand 2924XL switch and I've not been able to get in through the console port. I've not seen any output from it at all with a rollover cable that works fine on my 2600 router.
So far I have tried:
Using every speed from 115200 to 110
Hardware flow control on, and off
Xon/Xoff flow control (on and off)
I have been able to telnet in, but that's of little use without the passwords. Is there any other way of resetting it?