How come the Nintendo Entertainment System NES has a flashing grey screen when you put the game in?

One reason: Connection Error.

The thing is, when Nintendo made the North American and European NES, North America was going through the infamous video game crash of 1983. So in order for them to convince retailers to stock it, they called it an Entertainment System instead of a video game system(I heard it was originally supposed to be called the Advanced Video System or Nintendo Video System, which would make it AVS or NVS. It kind of sounds like "envious"). This is also the reason they marketed the system with R.O.B. to separate it from other systems.

Q: Okay, what does that have to do with my malfunction?

A: One thing to also convince retailers was its design. Instead of it being a top loader, it looks more like an old 8 track tape player, which explains why you can choose AV output(Future models were top loaders with only RF, but were talking about the original "toaster oven" one).

This explains why you have to push down on the game for it to read properly, but doing that for over 28+ years can bend the 72 pin connector, which is what reads the games. So then comes the dreaded flashing grey screen of death. The Red Ring of Death of the 80s.

Q: Does this mean my NES is as useful as a broken car?

A: Don't worry, it is completely fixable. Here are some solutions.

1: Do the old trick of blowing on your cartridges. But this only works if your system reads games every now and then. This won't help if your systems constantly won't read the games

2: Clean your cartridges with a Q-Tip and Windex.

3: Go out and replace the 72 pin connector. This is if all else fails. It may seem extreme, but its rather simple. All you need is a small Philips head screw driver, and a new 72 pin connector. You can find instructional videos and more on the web, and you can find the connector on Ebay or Amazon for $5 - $10.

Your system may mock you for now, but with this, you'll be playing with power again like in the 80s.