For models: TS4-1598415-NTS / TS4-1709194-NTS
Step-by-step guide
NOTE: If you suspect that you are not receiving any video. Try to get display using the VGA port, reboot system, and observe boot sequence. Splash screen should always display through VGA port.
Front/back view (TS4-1598415)#1598415-NTS/TS4-1709194-NTS)-SystemRearView
...