Is there any way without going to a repair shop to test a powerbook modem. I have tried various phone jacks, line and services. The modem worked until two days ago. Now it begins the dialing process (no audible dial tone, which I had before), and then stops. No clicking from the modem, just a faint whine/hiss. I have not downloaded or upgraded in since 10.2.5 was released. I have tried all of KB tips, and AOL and Earthlink tips. It is 10 months old, I have backed everything up, I just would like to know if there is any way to check the hardware withour taking it to a shop.