Hi, Emanuel Berg wrote: > [...] maybe it isn't > the case fans or the CPU cooling tower fans that make the > sound anyway! If nothing else helps to find the culprit, then consider to unplug all case fans to prove that it's not them. A bit more adventurous is to run the CPU without fan for a few seconds. (I assume from your fan list that it is a larger box where such manipulations are feasible.) Have a nice day :) Thomas