Likely or not, I cant say, but backplane connectors can and do fail. They're certainly not the part I've replaced the most, but it's not unheard of. It can also sometimes be a cabling issue, so you might try reseating the backplane cabling.   If you're seeing that the virtual disk is labelled as failed, then the best chance of bringing that data back (short of using a recovery service) would be by creating a new identical virtual disk and *NOT* initializing it. The intialization is what would cause the loss of the data blocks you're trying to preserve. This isn't guaranteed, so if you have any way of capturing a back up, I'd do that first.
I would appreciate some advice on a possible failed raid. Using T420, 8x 3.5" hot swap backplane on PERC H710. 8 drives in RAID10.   One drive lit up amber, the other 7 all green. So I put a replacement drive in the amber slot. However, the caddy light stayed off. I put the old drive back in, caddy light still stayed off. I rebooted, the light still stayed off, so I power cycled, still stayed off, on either drives. Is it likely that a backplane port can just fail?   Unfortunately, when I checked in IDRAC, I could only see drives 1-7, drive 0 did not show up at all, and the controller in IDRAC is telling me the raid had failed. I guess it is possible that this drive 0 and drive 7 where in the same span?   When restarting the server, I am asked if I want to import the foreign configuration of the controller. Could you help me in how to proceed so I can possibly recover the raid and data?
T420 failed backplane slot? RAID10 failure?