When I have a modem (ISDN terminal adapter) plugged into a USB port on my laptop, there is an abnormal amount of cooling-fan activity (about 75% of the time), even if the modem is not in use. Could this be because the modem is taking its power from the pc (even though the power consumption is very small)? I don't mind the fan kicking-in now-and-again, but to have it on most of the time is a real pain.

Has anyone any ideas how to solve this problem? Would an externally powered USB hub be the answer? I don't want to have to disconnect the modem every time it is not in use (that causes other problems described in another thread). I am using XP pro.

Any help would be appreciated.

Alan

This is because usually the majority of USB modems use the CPU cycles to do their workloads, which means even if ur not doing anything the modem may be doing something and hence usin CPU cycles.

You could try the following to see if it is the modem. Power down the computer, disconnect the modem. Start the computer. Then press, Ctrl-Shift-Esc to bring up the Task Manager. Just leave that run for about an hour. You can switch between the Processes and Performance tabs. Note the fan's cutting in and out.
Then, power down. Connect the modem. If you want to wait a while, do so. Power up. Again press Ctrl-Shift-Esc. For an hour note the fan cut in and what processes are running as well CPU usage when you go to the performance tab. If CPU usage is higher, it will normally run hotter.
If there is no change, then go online keeping the task manager operating in the background and watch the CPU usage - both when you are using your browser or when you have logged off.

Many thanks to all who have replied so far - I now have a few things to check-out and hope the problem can be solved.

Best...

Alan