R740XD BP2 SAS cable error

Hi everyone,

I'm new to the forums so hopefully I'm in the right place. 

I'm having an issue with my R740's mid bay backplane. The specific error I get is this: HWC2003: The storage BP2 SAS A0 cable is not connected, or is improperly connected.

My system has the following:

• H740P raid card
• 12x3.5" BP1 
• 4x3.5" BP2

Note: it does not have a rear flex bay installed

I've double checked all the cables' part numbers and where they're supposed to connect too, and they are correct. I've also changed out the cables to others I have on hand and the server produces the same error.

 

When I boot into the BIOS, I see backplane 1 (front bays) and backplane 2 (mid bays) show up in the system information. However when I look into the H740P's configuration utility, the H740P only shows backplane 1. Strangely enough, despite the H740P not listing BP2, the two drives in the mid bay still show up in the inventory in iDRAC but their disk numbers are reported incorrectly as disk 14 and 26. Or at least I assume those are incorrect. I figured this means that the SAS connection from the mid bay is in fact working and there's some error in reporting it either from the perc card or within iDRAC.

One final important piece of information though is that this motherboard is originally from a OEMR R740 non-XD. I purchased an R740XD chassis 3rd hand because I wanted to expand my storage options. After that swap it was working completely normally with the XD's front bay until of course I put in the mid bay at which point it throws that HWC2003 error. Some people I have talked to in other communities have suggested that this error might be because the motherboard still identifies as an R740 non-XD so it's not expecting backplane zero or backplane two to be installed. However, from all my reading online, it seems like the right ear of the chassis lets the motherboard know either it's supposed to be an XD or non-XD.

Any suggestions would be much appreciated, thanks!