Hi everybody. I'm experiencing a recurrent problem JBL's MP-418 amp. It seems that, after a while, they are having trouble evacuating the heat. I tested a brand new unit, out of the box with a pink noise running and peaking slightly on 4 ohms load, full power ( both sides with low pass on for hours without problem The units I get for repair mostly have the same problem; they cant take this test for more than 30 minutes before going on thermal fault. Electronically speaking, everything look fine. I found that, reversing the fan i.e. having it pushing air into the unit instead of pulling it, the amp stay on a lot longer. In fact, as long as the new unit. But I'm sure there must be a reason why fans are pulling air ... and this is not a final solution. So I was wondering if any of you out there ever witnesses the same problem; and, most important, found a solution.