MFC just "Exhaust-Fan after long usage

[Kyruss]

Hi, i have problems with three iMacs (Modell 11,2 , 12,1 , 12,2)
they were upgraded with Samsung 850 Pro at macos 10.10.4 and now they are at 10.12.4...

now the only Fan i see is an "Exhaust" ... but i remember after the upgrade to SSD on 10.10.4 there were 3 Fans (CPU,HDD and Ram ... i beieve...)

i´ve removed MFC, deleted the plist in user/library/preferences and reinstalled after an smc reset...
but still, i see just the "Exhaust"

i reinstalled one of this iMacs with an clear 10.12.5 image and got all three Fans.... 

could you help me with some ideas ?  - i wont reinstall the other macs iMacs

Thx
Ky

PS: Sorry for my bad english...

[Steven]

Hi,

Frankly speaking, I don't know. This if the first report like that. Maybe some SMC bug? I'd reinstall clean system on all macs.