You had a 846A chassis with a TQ backplane ? it should be a BPN-SAS-846A backplane instead !I have a SC846 (SC846BA-R920B to be exact). I've replaced the TQ backplane (no expander) with BPN-SAS3-846EL1 SAS3 backplane with expander. It was not hard to replace, took maybe 10 minutes total.