OK guys....I experience occasional bouts of overheating on my normally fast, 2gig ram dell inspiron 9400. It should idle at 40degC (according to the i8kfangui temp utility) but when it get's unhappy from time to time it idles at 50degC, and all other temps seem to be inflated 10 - 15 degs above normal. I usually sweep for spyware, hijackthis etc, and when I find the system's clean I then unplug all USB devices and then plug them in one at a time. This normally cures my overheating problem, and the idle returns to 40deg.
However, this time it's a bit more difficult to solve. Using the real time graphs from the temp monitor I can watch the CPU temp rise 10degrees in about 10 to 15 seconds right after I plug in my usb devices. As soon as I unplug the device(s) the temp falls back to 40deg. I've done this enough times to verify the cause and effect: it's not simply a coincidence.
Now I'd expect plugging in a USB device to cause a brief spike in CPU use, but what's strange is that even after the CPU usage has settled back to 1% (a few seconds) the idle temp remains at 50deg, until I remove the USB device, then the temp immediately falls back to 40. It's quite disconcerting. I've tried this with a bunch of different USB devices (flash drive, bluetooth dongle, mouse etc) to check that it's not just one device or socket.
So I'm at a loss what to do. I know something's wrong because normally the laptop idles at 40deg, even with ALL usb devices plugged in. So I need a way to 'reset' the USB devices to stop pumping up the temperature on my CPU. So please don't tell me that USB devices drive my system hotter under normal use - I'm sure they do - but when it's healthy my laptop can handle ALL the usb devices and still idle at 40deg. Something must be causing a hardware conflict and I'm eager to sort it out to stop my fan coming on all the time!
Thanks guys, JT
