I just bought a TCL 435S525 smart TV. I want to be able to connect and older Magnavox MDV455/17 DVR to it which I believe requires an RCA to HDMI adapter. The TV has a yellow colored AV adapter plug, but the adapter did not come with the TV and is noted as not coming with it in the setup instructions. Can I just buy and AV adapter plug and use it for one device and buy an RCA to HDMI adapter to hook up the other? One of my old VCRs is a sony SLV-340 with only 2 black plugs and 2 yellow plugs. I believe this is due to it being a mono and not stereo sound. How does that old thing hook up? I hate to buy new tech. It gets outdated and cheaper so fast. I only bought the flat screen because my old cathode ray tube gave up the ghost a few months ago.