UPDATE! SWAPPED TO DIFFERNET CHASSIS Thanks for your reply, Stefan — I was nearly certain firmware update wouldn't work if I couldn't even probe to get the existing version so didn't think it was a good idea to try.  I get very anxious doing firmware updates for fear of bricking something. But interesting news! I swapped for a different chassis today and fans seem like they are WORKING great now. Still need to mess with the system to see if they are adjusting speed properly.  There are SO many settings and data points available in iDRAC that I was not seeing before. As I'm new to Dell enterprise hardware I had no idea what I should be seeing. But a BIG clue to anyone else facing these types of symptoms -- I was not seeing power supply info, fan speeds and the message "RAC0709: Unable to retrieve the fan information" as I mentioned in original post were conditions suggesting that the sled was not properly communicating with the chassis. Once I powered up this chassis with only a single power supply inserted, I immediately got flashing power button and indicator lights that I hadn't seen on the previous chassis. So something was definitely wrong with that previous chassis.  Among the theories I have been mulling over that may have been the issue with the original chassis I had.... So here are what I think are clues that the sled(s) are not communicating with the chassis (my theory as to the issue I was facing)…. All that stuff and more now appears in my iDRAC interface.  Having not been a Dell or PowerEdge C user before I didn't know how much was missing. I still plan to update firmware and will update this thread with any info that might be helpful.   I can now probe for versions using IPMI….  so I think I have 1.25 version ipmitool -I lanplus -H 192.168.50.16 -U root -P ***** raw 0x30 0x1201 7e 1b 01 25 00 00 00 00 01 ff 00 01 24 2e ffff 0f c2 00 00 01 04 01 04 31 c5 11 ff 0f
Hi folks -- having a heck of a time trying to understand what is going on with the fans in this C6300 chassis I'm trying to turn up.  SYMPTOM: The fans for the left two sleds are going full blast (assuming) and the fans on the right two slots are either not working or are barely turning.  (I disconnected the left side and these right side to try to discern and the right side do seem like they are turning but barely. I could be wrong and they are just dead or turned off. OBSERVATIONS: TROUBLESHOOTING:  NEXT STEPS (please provide feedback, guidance, tips and suggestions... thanks!)  
Half of C6300/C6320 Fans Don't Work