Could be a million things.
As it is all new gear call IBM.
Go to
IBM United States, hover the mouse over "Get Support" then when the pane updates select "Open a service request". Follow the instructions.
Because you can see the system from the HMC and the terminal seems to open - but there is no login - I suspect there is a terminal / console definition problem on the
AIX installation.
If it was preinstalled then it was probably a standard load that has the wrong console device configured.
You could try activating the partition and select booting to SMS, then (if the console works at this point) take option 4 to configure the console.
Otherwise you may need to detatch the HMC and power off then on the system (to let it know it is no longer managed by an HMC so that the service processor will reactivate the serial ports) and use a serial console to access
AIX / the LPAR to reconfigure the console device in
AIX.