Dell JY1GC is a two-port SAS/PERC cable option for the PowerEdge R250, intended for a two-drive cabled configuration with a PERC controller.
Dell lists this part for R250 systems using the PERC H355 or H755. The service manual’s two-drive PERC layout routes the HDD0 and HDD1 signal connections to the controller’s CTRL_SRC_SA1 connector. Their power connections go to HDD/ODD_PWR on the system board.
This cable is the two-port R250 option; Dell identifies 38NC4 separately as the four-port cable.