I have the same problem.
the MSKBsC gave me a '"check Pass" so is not the cipher problem.
Just to make sure, other clients machine are able to connect to my sql server using the default instance and sa as user account.
My envirorment fresh VM win 2012 server + IMC 7.3 SD + MSQL 2014 - trial.
I follow both documentations:
HPE Intelligent Management Center SQL Server 2014 Installation and Configuration Guide
HP IMC Centralized Deployment Guide with Local Database
Start checking installation environments...
By envheck results:
Checking ports occupied...
Passed
Checking physical memory size...
Passed
Checking database installation...
Passed
Checking database connectivity...
Not Passed