loud cooling fan on Studio 12G

I purchased some Studio 12G recorders couple years ago, and recently acquired a couple more. I noticed the cooling fan is louder than those previously purchased. These are not loud that it drowns out conversation but previous models were much quieter.

Question I have for others out there notice this? Or maybe the first batch the fans were not running?

EDIT: oops, jumped ahead too soon to the forum. I just checked again, fan noise same. I was comparing to a Studio 2 and also previous check was in a room that had more background noise.