The fan works -- and runs at different speeds, but it won't run faster as the Readynas gets hotter and hotter. It was fine until I switched to two new drives -- WD20EARX and upgraded the Bios. Now, its starts at 70 or 80 degrees and gets to 130 degrees F until I shut it down. The fan is running, but maybe just 294RPM or higher, but not high enough. Sounds like a fan problem, yes, but was wondering if there was any option other than replacing the whole unit that I just bought two new drives for!