The Zalman ZM600-HP power supply is cooled by a single large 120mm ADDA fan (AD1212MB-A71GL) which is temperature controlled. During testing the ZM600-HP power supply was definitely very quiet would be inaudible when installed into a system. Zalman clearly states on the power supply sticker that there are no user serviceable parts inside the PSU and the fan is soldered to the power supply PCB. There is even a blue LED under the fan to give it a nice back-lit effect when. The fan itself is not illuminated though.

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