Sellers always appreciate it when a buyer contacts them first with any issues to give them a chance to make it right.
If the listing says the games and console are tested and working, then that is an item not as described case. Every seller with a large inventory is going to let a few mistakes slip through. What makes the difference is how it is handled.
As I stated above I would give him a chance to make it right. Ask him to take a complete return, including shipping.
If he does not take the full return then that is when I would consider neutral or even negative feedback depending on his attitude. Also open a case. If he does take the return and you think he needs it, you can leave a positive while saying something like "item was listed as tested but did not work. Seller accepted return.". This will warn future buyers, but with 100% he is likely not a bad seller and did not do it on purpose.
Oh, and one more thing. I sale older consoles and I always test them. I tested an Xbox 360 and it worked fine. Then 3 weeks later after I left it out in my hot camper, I tried to play a game with it and it did not work. When it comes to old stuff it is possible that things can go wrong w/o a seller knowing.