the other day I received the shiny new MW PSU that Open Builds sent to replace one I bought recently. I printed up a terminal cover with power switch and with voltmeter in hand, powered up the PSU. The fan didn't come on. I said a dirty word (I had already shipped the old unit back and don't own a fleet of PSUs) and wanted to resume setup on my Delta. In case the power switch had gone bad I removed it and hooked the power cord directly to the PSU. Left the terminal cover off. Plugged it in and voila, the green led lit up. Voltmeter informed me that 24.0 volts were streaming out. Still, no fan action. On the old unit the fan started (with gusto...read: noise) whenever the unit was powered up. So, is the new PSU faulty, or does the fan only start when the unit gets warm? Thanks for any advice (or ridicule) you care to offer.