M4300-x24 OVERHEATS and runs WAY too hot. Need internal fan speed increase

We have 8 x M4300-24x switches.  They work great!  great performance, BUT they constantly run around 68 degrees Celcius.  WAY WAY too hot.  We've had to return 4 of them for replacment because they burn up.  Checking the system environment info, it says the internal fans are ONLY running at 17%.  WHY??  If we could crank these up to 50% or 75% it would probably get all that HOT air out of the system, and stop them from burning up.  They are in a cooled computer room, so noise is NOT an issue.  I thought I saw some community post where they said there WAS a patch to increase the fan speed.  HOW do I get a hold of this before we burn up MORE of our units?  Please help!