I have implemented the
@RoachedCoach Mechatronics and Sunon fan mods discussed
here on a ICX7250-48P. The new fans are definitely quieter, but I am not getting the results that others have. From a cold boot, the ASIC temps rise to mid-60's which is no problem, however the air outlet temps rise to the speed 2 threshold, the fans go to high and the temp drops to exactly 34c, the threshold for dropping back to speed 1. So once speed 2 becomes active, it never drops back. I tried just running with 1 fan, air outlet temps go into the 60's, but still have the one fan running at high speed. With the fan(s) running at high speed, the 7250-48P is louder than a 6610-24F with 2 Rev. A power supplies.
Due to a comedy of seller errors, I also have a 7250-24 and 7250-24P with dead PoE. The 7250-24 with its single OEM fan runs happily in the same rack with the fan at low speed. But I am not fond of the idea of going back to PoE power bricks.
Any ideas on getting a 7250-48P cool enough so the fans run at low speed?