Dell KKMYD Display Port to DVI Video Dongle Adapter Cable DANARBC084 Optiplex 780 : Electronics
Optiplex 780, 2408WFP, HDMI not working - Dell Community
Refurbished: Dell OptiPlex 780 USFF Desktop Intel Core 2 Duo E8400 3.0GHz 4GB DDR3 RAM 250 GB HD DVD-RW WiFi Bluetooth Microsoft Windows 10 Pro - Newegg.com
Dell DisplayPort to DVI Single Link Adapter DP/N: 0KKMYD : Electronics