Hi, Thanks for the reply.   I took a "hail mary" and removed the backplane for cleaning.   During the removal, I noticed that clips holding the board in place were pretty flimsy.  I applied pressure to the back of the backplane board as I reinserted each drive.  Sure enough, the clip on the bottom right corner was allowing the backplane to flex a little as the drive carrier tried to get seated.   That fixed it. Cheers  
I'm upgrading the 8 disks on my Poweredge 2900.   Before the upgrade, all slots worked fine.  All the new drives are HGST 2TB SAS.   When I installed them, all the drives report healthy except the drive in Slot 4.  It always reports an error (yellow blinking light).   I have swapped the drives around and they all work fine in any other slot.  It doesn't matter which drive (or carrier) I put in slot 4 - always the same error so I'm pretty confident it's a slot issue. I suppose there's a chance the slot died during the upgrade but the chances seem slim.  Any ideas on how to confirm the slot really has died or possible ways to eliminating the error?    I really need all the slots to work since the raid is PERC 6/i and therefore only supports drives up to 2TB. Thanks in advance.
Poweredge 2900 Perc 6/i slot failure?