M1000e Fans at full speed

Greetings, 

During a recent addition of a new M620 server to a chassis where 3 other existing M610 servers were already living we encounted a problem in which the fans blast at full speed as soon as the new server finishes booting and loading the OS. We followed support´s instructions and updated every piece of firmware on the chassis (dual CMC) including IOM cards (redundant M6220 switches, ethernet passthrough, and Brocade M5420 FC switches) and still no help. Firmwares were also updated on the M620 to the latest versions including iDRAC.

No CMC errors reported and no alarm lights on the chassis either. Support is now saying that it might be related to an incompatibility issue between the new server and the chassis´ backplane which is version 1.0. They claim these new servers were designed to work with the newer version 1.1. 

This of course makes no sense at all as there isn´t any information either on DELL support site´s documentation that sustents this claim. 

The specs on the new M620 server,

2 x Intel Xeon CPU 8C E5-2680

96GB of RAM

H310 mini PERC RAID controller

2 x 146GB 15k RPM SAS HDD

iDRAC Enterprise w/ 8GB vFlash

2P Broadcom 10Gb LOM NIC

4P Broadcom 1Gb NIC on mezzanine B

2P QLogic 8Gb FC HBA on mezzanine C

The chassis has 6 redundant powersupplies

Dual CMC controllers

Temperature running a steady 15C

Anyone run into this problem before???

Thanks.