The Embedded DisplayPort (eDP) cable transmits video data from the logic board to the LCD panel. There are two eDP cables for 21.5" iMac computers released Late 2015 and this cable is only compatible with those that have Retina 4K displays. This eDP cable for use with 4K Retina screens uses a cable with a 40-pin connection on the logic board and a 60-pin connection on the LCD panel. The non-Retina eDP cable has a 40-pin connection on the logic board but only a 30-pin connection on the LCD panel. This cable may be referred to as an LVDS cable due to widespread usage of the LVDS protocol in earlier Apple devices which was later replaced with Embedded DisplayPort.
923-00608 Display Port Cable for iMac 21.5-inch Late 2015 A1418 MK452LL/A, BTO/CTO This is a replacement Display Port cable for the Late 2015 iMac 21.5" Retina models.