The installation engineer may just be right!
2240 systems in an HA pair with no external SAS storage may use single-path HA, which requires no external cabling. However,the recommended configuration is to enable Multipath HA for the internal disks by connecting the SAS ports of one controller module to the SAS ports of the partner.
As per the cabling guide for FAS2240-4:
https://library.netapp.com/ecm/ecm_download_file/ECMM1280392
For fault LED you can try these steps:
1. At the Data ONTAP CLI prompt, issue the “halt –s” command. Please note that this will cause an HA takeover in an HA configuration.
2. Wait for the controller to shut down .
3. On the console port (not RSH, SSH, etc.), issue a “^G”(ctrl G)to switch the console to the SP
4. Log in to the SP.
5. At the SP prompt, issue the “system power on” command.
6. Issue a “^D”(ctrl D)to get back to the Data ONTAP console.
7. Once the BIOS / Loader have booted, issue the “boot_ontap” command.
8. Issue Giveback after Takeover.
For HA configurations, the partner will also need to go through the 7-step process.
Thanks,
-Ashwin