Cheetah 125+ Joystick Repairs

I recently bought a large job lot of vintage computer equipment, among which were about twenty joysticks in varying condition.

These had been stored for decades and required a good clean-up; all worked fine except for four Cheetah 125+ models, which had varying problems.

A couple of them were in their original boxes, and I really hate writing equipment off for spares unnecessarily, so I figured I’d have a go at repairing them.

Most joysticks are a fairly simple construction, these ones included – only four case screws hold the bottom on, revealing the inside.

Some quotes from one of the boxes, which I found entertaining: “deluxe”; “robust construction”; “rugged hand grip”; “heavy-duty base”; “highly sensitive, light touch fire buttons”; “extra-strong direction/fire contacts”.

As you can see from the image above, this thing is cheaply-made garbage!

Rather than using micro-switches like the more professional joysticks (i.e. ZipStiks), each direction uses a leaf-style contact, and the secondary fire buttons are just a sprung metal disc taped over a contact on the PCB – these methods are less reliable than switches, and make the joystick feel very limp, rattley, and unintuitive.

Joystick #1

Joystick #1 had intermittent left and right directions, and whilst the triggers worked fine, neither of the secondary fire buttons worked.

Cleaning off the underside of all the leaf contacts with a nail file fixed the direction issue, and removing, cleaning, and re-installing the button contacts fixed the button issue. 100% OK!

Joystick #2

Joystick #2 had no working directions, and whilst the triggers worked fine, neither of the secondary fire buttons worked.

After dismantling the joystick, I noticed that all the screws which contact with the leaf springs to form a switch were coated in rust – this was probably caused by long-term storage in a humid environment.

Soaking these in white vinegar overnight then reinstalling, then cleaning off the underside of all the leaf contacts with a nail file fixed the direction issue. Removing, cleaning, and re-installing the button contacts also fixed the button issue. 100% OK!

Joystick #3

Joystick #3 had non-working left and right directions, and whilst the triggers worked fine, only one of the secondary fire buttons worked.

Removing, cleaning, and re-installing the button contacts fixed the button issue. However, cleaning off the underside of all the leaf contacts and topside of the contact screws with a nail file did not resolve the left direction issue, nor did tightening all of the connections or adjusting each of the springs, though I was able to get the right direction working again.

At this point, it made sense to check for electrical continuity between the switch output and the joystick connector (using a spare male connector to make the pins easily accessible for testing).

On all Atari-compatible joysticks, the connector has four digital outputs for directional data (up, down, left, right), one digital output for fire (some joysticks also have an auto-fire feature or multiple fire buttons, which are wired in parallel), and two analogue outputs for paddle signals.

In this case, there turned out to be a break in the left-direction wire somewhere between the connector and the cable entry into the joystick, probably caused by cable stress – this is not easily repairable, so I’ve confined this joystick to spares.

Joystick #4

Joystick #4 had non-working up and down directions, and whilst the secondary fire buttons worked fine, neither of the triggers worked, and both felt really notchy – the case also had some cracks, so I suspect that this one has been crushed or dropped at some point.

After dismantling the shaft to try and repair the triggers, I found irreparable damage to the trigger mounts, so I’ve confined this joystick to spares.

Conclusion

Looking for a serviced joystick for your Atari-compatible computer or console, or want to try and repair one of the spares ones? All of these joysticks are currently available for sale on my eBay page.