What are the three jacks of the old projector?

As long as the interface types of the cable TV box and the projector are the same, there is no need for patch cords, and a direct line can be used, in which the AV interface uses a common video cable, and the general connector is a lotus male terminal at both ends; The HDMI interface uses an HDMI cable, and the connector is also an HDMI dedicated head; The YPbPr interface uses three video lines, and the general connectors are shower heads at both ends.

Most home projectors don't have built-in speakers, so you need to find another sound system to generate sound. A few projectors with built-in speakers use a 3.5 three-core interface, which requires a cable with a double lotus male head at one end (connected to the set-top box audio) and a 3.5 three-core plug at the other end.