The good news is that it’s one of the easiest faults in retro gaming to fix properly.

What’s actually going on

The front-loading NES (model NES-001) holds the cartridge in a 72-pin connector. When you press the cartridge down, the connector’s spring pins clamp onto the cartridge’s edge contacts. After decades of use, two things go wrong:

• The pins lose their tension. They’ve been bent open and closed thousands of times, so they no longer grip the cartridge firmly.
• The contacts get dirty or oxidized. Both the connector pins and the cartridge’s gold contacts collect grime, and some cartridges show green or black corrosion.

That bad contact matters because of the 10NES lockout chip. Nintendo put an authentication chip in every console and every licensed cartridge. When you power on, the console’s chip talks to the cartridge’s chip. If it can’t get a clean answer, it resets the console about once a second. That reset loop is the blinking light.

So the blink usually isn’t a dead console. It’s a console that can’t hear the cartridge clearly.

What helps (and what doesn’t)

Don’t blow in the cartridge. It feels like it works because reseating the cartridge sometimes lands the pins on a cleaner spot. But the moisture in your breath speeds up corrosion on the contacts, so every blow makes the next failure more likely.

Do clean the cartridge contacts. Use a cotton swab with 90% or stronger isopropyl alcohol, rub the contacts on both sides until the swab comes away clean, and let it dry fully before inserting. This alone fixes a surprising number of “broken” games.

Be careful with home connector tricks. You’ll find guides for boiling the 72-pin connector or bending the pins back by hand. These can buy some time, but results vary and it’s easy to end up with uneven pins that grip some cartridges and not others.

The proper fix

A lasting NES blink repair looks like this:

1. Replace the 72-pin connector with a new one, so every pin grips evenly.
2. Clean the board edge where the connector seats.
3. Test with a stack of cartridges, including a few known-difficult ones, through several cold starts.

What about the top-loader?

The later top-loading NES (model NES-101) doesn’t have this problem nearly as often. It uses a direct card-edge slot instead of the push-down connector, and Nintendo removed the lockout chip from it. If you own one and it won’t boot, the cause is usually somewhere else, like the power supply or a dirty cartridge.

If your NES is blinking, clean your cartridges first. If it still blinks, a new connector will almost certainly sort it out. We repair NES consoles, so get in touch if you’d rather have us do it.

Why cartridges need a battery

Many Game Boy and Game Boy Color games save to a small chip called SRAM. SRAM only holds data while it has power. To keep your save when the console is off, the cartridge has a coin cell battery soldered to its board, usually a CR2025.

Those batteries were never meant to last forever. Many have lasted 15 to 25 years, which is far longer than anyone planned for, but a lot of them are now at or past the end.

Signs your battery is dying

• The game won’t keep a new save. You save, power off, and the save is gone when you turn it back on.
• The save is missing entirely. For example, there’s no “Continue” option on the title screen of a game you know you saved.
• The clock is wrong or stopped in Pokémon Gold, Silver and Crystal. Those games use the same battery to run their real-time clock, so day/night and time-based events stop working properly.

The Game Boy Advance games are different

Pokémon Ruby, Sapphire and Emerald store your save in flash memory, which doesn’t need power. Their battery only runs the in-game clock. When it dies, you’ll see this message:

The internal battery has run dry. The game can be played. However, clock-based events will no longer occur.

Your save is safe in that case. You’ll just lose things like berry growth and tides until the battery is replaced.

Replacing the battery without losing your save

This is the important part. On SRAM games, removing the old battery wipes the save. Pulling the battery out and popping in a new one will give you a working cartridge with an empty save file.

Here’s the safe way to do it:

1. Back up the save first. Read the save off the cartridge with a dedicated cartridge reader and keep it as a file.
2. Swap the battery. Remove the old battery and fit a new tabbed CR2025, soldered in properly. Avoid tape or a loose coin cell wedged in place.
3. Write the save back onto the cartridge and confirm it loads.
4. Keep the save file somewhere safe, so you have a backup even if something happens to the cartridge later.

Which cartridges have batteries?

As a rough guide, any Game Boy or Game Boy Color game that saves progress, rather than giving you passwords, probably has a battery. That includes the Pokémon games, The Legend of Zelda: Link’s Awakening and many RPGs. Many Super Nintendo cartridges that save use the same kind of battery, usually a CR2032.

Not sure about yours? Ask us with the name of the game, and we’ll help you find out.

That isn’t nostalgia playing tricks. Old consoles and new TVs really don’t speak the same language.

Why it looks bad

Most consoles from the NES through the PlayStation era output a low-resolution 240p picture. CRT televisions handled that natively. Modern TVs mostly don’t recognize 240p, so they treat it as 480i, an interlaced signal, and run it through their deinterlacing and scaling hardware.

That causes three problems:

• Blur and shimmer, because the TV is guessing at lines that aren’t really there.
• Input lag, because all that processing takes time. You’ll feel it in platformers and fighting games.
• Wrong shape, since everything gets stretched to widescreen unless you set the TV to 4:3.

Step 1: Use the best cable your console supports

From worst to best, the old analog connections go like this:

Some consoles can do RGB with just the right cable, such as the Super Nintendo and the Sega Genesis. Others, like the NES and the North American Nintendo 64, need an internal mod first.

Step 2: Put an upscaler in front of the TV

A dedicated retro upscaler takes the analog signal, understands 240p properly, and sends your TV a clean HDMI picture with very little lag. Popular choices include the RetroTINK line and the OSSC (Open Source Scan Converter).

Skip the cheap composite-to-HDMI boxes. The inexpensive adapters sold online often make the picture worse and add their own lag. They work as a last resort, but a proper upscaler is a very different experience.

Step 3: Consider an internal HDMI mod

For some consoles, you can go fully digital. There are internal HDMI kits for the Nintendo 64, and the GameCube’s digital video port can be converted to HDMI. These give the cleanest result with a single cable, and the console stays in its original shell when the install is done well.

When a CRT is still best

A good CRT television still has zero lag and handles 240p natively. It’s also the only option for light gun games. The NES Zapper in Duck Hunt relies on the timing of a CRT’s picture, so it won’t work on an LCD or OLED screen at all.

What we recommend

• Casual play on one console: the best cable it supports, plus setting your TV to its game mode and 4:3.
• A shelf of consoles: a quality upscaler with RGB or component cables.
• One console you play constantly: an internal HDMI or RGB mod.

Not sure what your console and TV need? Send us a question and we’ll point you in the right direction.