OK, soooo...... this Megadrive 1 is knackered, graphics all wonky and just generally not displaying, it " could " be the V-RAM chips, only problem is, I don't have any spare, shall we see if a couple from a Megadrive II will work? :p
I guess its time to buy a second Mega Drive 1 with problems haha I did the same with the 2x master system 2 systems the audio chip was defective on one