Reviving the joystick everyone had

Two ways a CX40 wears out, and the rebuild that fixes both.

The Atari CX40 joystick—one stick, one red button, a black rubber boot—is the controller everyone pictures when they think of the Atari 2600. The 2600 launched in 1977 with the earlier CX10; the CX40 that replaced it about a year later is the one that became iconic. By 1983, roughly one in five American homes had one. Its nine-pin plug also became a de facto standard, adopted by Commodore, the Atari 8-bit line and ST, MSX, and Amiga. These were well-built controllers, not flimsy ones—but after years of play they have two well-documented ways of wearing out, and one of mine had finally hit both. Here's what's inside a CX40, why they eventually fail, and the rebuild that fixes it for good.

A little background—the controller everybody held

The CX40 was the 2600's pack-in stick for most of the console's long life, and it stayed in production for around two decades—which is a big part of why it became as recognizable to Atari as the Fuji logo. One stick, one button—and that was enough for Adventure, Pitfall, and most of a decade of gaming.

The other reason it spread everywhere is the connector. The CX40's nine-pin plug became the first widely used cross-platform game-controller connector. Commodore's VIC-20, 64, and 128, the Amiga, and the Atari 8-bit computers all wired it the same way Atari did—pin 8 ground, pin 6 fire—so a plain single-button Atari stick drops straight into any of them. Other machines borrowed the same connector without the same wiring: MSX, for one, puts its ground and second fire button on different pins, so a CX40 that fits won't simply work there. But across the Atari-wired machines it became a real standard, which is why a controller this old still has a job in my workshop today.

What's actually inside

Four screws, two case halves, and a surprisingly simple machine. Open one up and you find the white inner handle, a small circuit board, a wire harness, and the DE-9 cable. The board does the switching: five silver metal dome contacts sit over copper pads—four arranged in a cross for the directions, a fifth offset to one side under the fire button—held down by a thin clear adhesive film. The orange "TOP" molded into the case tells you which way it's meant to face.

A CX40 opened on the bench—four screws, two case halves, the stick and boot, and the orange "TOP" ring.

The handle sits on a post through the center of the board, and the underside of its dome has four little fingers resting over the directional contacts. Push the stick and a finger presses a dome down onto its copper pad, closing that switch—and the geometry only lets two neighboring contacts close at once, which is how one stick gives you eight directions. The contacts and that inner handle are the parts that wear.

The original contact board—five silver dome contacts over copper pads, held down by a clear film. This is what wears out.

Why they fail

Two things wear out, and they tend to feed each other. The first is the inner handle: the thin ring at its base, and the four small tabs that join it to the stick, take the force of every shove, and on a well-used stick they can crack—period reviewers reported it happening "with distressing regularity." The second is the contacts. After enough presses a direction stops registering—and as BEST Electronics, the longtime Atari parts house, points out, it's usually not the silver dome that's gone bad but the copper pad on the board beneath it, or the clear film holding the domes drying out and letting them shift. As the contacts weaken, you press harder, which is what eventually cracks the handle—so the two failures chase each other.

New inner handle (left) next to my original. Decades of use yellowed the old one and cracked its lower control ring—the part that takes the force of every push.

Mine had hit both at once—a textbook example. The contact for the left direction was crushed, so left had gone dead, and the inner handle's lower ring had cracked. That's the feedback loop in a single unit: as a worn contact stops registering, you lean on the stick harder, and the extra force is what finally breaks the handle. Set my old handle next to a fresh one and the cracked ring is obvious. Either way, the cause is years of honest use, not a design that was ever flimsy.

The break, close up: the lower control ring on my old handle has cracked away—one of the two classic CX40 failure modes, and the reason the stick stopped pressing its contacts.

The fix: don't restore the failure mode

You can buy new-old-stock Atari internals, but they're the same parts that wore out the first time. BEST Electronics—the Atari parts house in San Jose that's been at it since 1984—takes a different approach. Rather than re-tape a few replacement domes onto a tired board (BEST notes those cheap dome kits fail fast, because the reused tape lets the domes "walk" out of position), they sell a complete redesigned board: the CX40 Lifetime Gold PCB, with gold-plated contacts that resist the wear that kills the original copper pads. It's their own design, now in its fifth generation—the board I fitted is marked "Rev. 5." Their standard advice is to replace the board and the white inner handle as a matched set, so that's what I did.

The BEST Gold Lifetime PCB with the wire harness laid against it—gold-plated contacts and the labeled wires (BRN, WHT, BLK, BLU, GRN).

The rebuild

The job is friendly—BEST rates it at "change a tire" difficulty, and that's about right. Four screws, then the old board lifts out. The six color-coded wires—brown, white, black, blue, green, orange—each end in a flat slide-on spade connector that pulls off the old board's edge tabs and pushes onto the new board in the same order. There's a small fire-button spring under there that's famously easy to lose, so I set it aside first. New Gold board in, new inner handle seated, case back together over the four screws. Nothing fought me, which is part of why these have stayed repairable for decades.

The verdict

It felt great during play-testing—firm but responsive, with a satisfying click on every direction that a stock CX40 never had. That click is the sensory difference: the Gold boards give you positive feedback under your thumb, where the original domes are mushy by comparison and getting mushier with age.

For the rigorous testing phase I plugged it into the Atari 800XL and played Donkey Kong on the Commodore 1702. The stick is older than most of the people who will read this, and it just earned a service-life extension its designers never planned for. That's the part I like: not a museum restoration frozen at factory spec, but a working controller fixed so it keeps working.

Field testing, rigorously: the rebuilt CX40 running Donkey Kong on the Atari 800XL, displayed on a Commodore 1702.

Questions I get about CX40 joysticks

Why did my Atari joystick stop working in one direction? Usually one of two things: the contact for that direction has worn out—and it's typically the copper pad on the board that degrades, not the silver dome sitting on it—or the lower ring on the white inner handle has cracked, so the stick no longer presses that switch. Both are wear, not damage, and both are fixable.

Can you still buy parts for an Atari CX40? Yes. BEST Electronics in San Jose carries both original-style internals and a redesigned Gold Lifetime upgrade PCB, along with handles, boots, springs, and cables.

Is the BEST Gold PCB better than original Atari internals? It's a full redesigned board with gold-plated contacts that resist the wear that kills the original copper pads, rather than a like-for-like replacement that would fail the same way. BEST recommends fitting it together with a fresh inner handle as a matched set for the longest service life.

Will a rebuilt CX40 work on my Commodore or Amiga? On the Atari-wired machines, yes—the VIC-20, C64, C128, Atari 8-bit computers, and Amiga all use the Atari joystick wiring, so a single-button CX40 plugs right in. Watch out for lookalikes, though: some systems (MSX, and later Sega pads) use the same nine-pin connector wired differently, so a stick that fits won't necessarily work.

Further reading

• BEST Electronics — CX40 joystick rebuild kit and the Gold Lifetime upgrade PCB
• BEST Electronics — CX40 rebuild instructions and parts history
• Atari CX40 joystick — Wikipedia (construction, failure modes, and history)
• Atari joystick port — Wikipedia (the nine-pin DE-9 standard)
• U.S. Patent 4,349,708, "Joystick control" — James C. Asher, assigned to Atari (granted 1982)
• Atari vs. Wico: two trackballs, opened up (a sibling teardown from the bench)

I'm Jeffrey Mays. Bench Notes is where I write up the actual workshop work—burns, builds, repairs, and the occasional decades-old controller talked back into service. If a flaky Atari stick is on your bench too, now you know what's wrong with it and how it gets fixed for good.