The Wii outputs Analog Video only (Composite 480i, Component 480p). It has no HDMI port. Most modern Sylvania TVs are HDMI‑only (no Composite/Component inputs). You need an active converter.
Recommendation: Spend ~$25–40 on a Wii Component Cable + Quality Component‑to‑HDMI Converter (e.g., Portta, Musou, Kaico). It provides the maximum 480p clarity the Wii can output.