So after a little reading, I’ve discovered my issue with the Sega Master System is the result of having a TV that can’t properly receive the signal from the Master System itself. This is mostly a relief, as it means the System itself is fine and healthy and I just need to get either an older TV, or a VCR that can pass through the signal to from the Master System to the TV. Decisions decisions.
Also, I picked up a boxed Master System 2 yesterday that contained some loose Sega cartridges in the box that the seller wasn’t aware of (bonus!) and one of them had no label. I dubbed it the mystery cart, and spent a bit of time wondering what secrets it might hold. Disappointingly, it turned out to be Super Monaco GP 2. Bah.