Recently I found an old DVD player in my garage. It seems like the speakers work fine, but can I connect it to my PC instead of CD/USB? I want them work as my PC speakers.
Am I able to connect RCA to laptop cable to the DVD player input?
You can use a 3.5mm jack to phono cable. A simple internet search will provide a bountiful supply of purchasing options.
The cable you have includes a video input (yellow), you could use that cable and leave the yellow plug disconnected.