Symmetra RM showing an "internal communication failure"

[Anonymous user]

I recently had the batteries fail on this unit, showing a "internal temperature exceeded" which I found was due to a low center tap voltage in the sense circuit.  On restart of the unit, it will power up and report everything is operational until I turn on line power at which point it shows the internal communication failure with the RIM.  The unit will switch into bypass, but won't go online.

Is there any additional checks or troubleshooting I can do?

--UPDATE--

The UPS will also come up with line power in maintenance bypass and everything plugged in but the battery.  All report OK in Diags until the battery goes in, then I get an internal communication failure and both Power Modules and the RIM report "NoCom-MIM/RIM".

I might also add that in troubleshooting the original battery issue I pulled both the MIM and RIM at the same time, even though loads were off at the time.  I now read that this is bad.  Is there a reset procedure to get everything back in sync?