The 3DO Interactive Multiplayer (or simply 3DO) is getting old in terms of video game consoles. It's pushing 30 years old and has moving parts that need to function properly to be able to read the CD-ROMs. Sometimes those parts fail or are failing.
I have a Goldstar 3DO player that when it was powered on the CD drive would immediately open. I pushed the Open/Close button to close it and the disc tray would close all the way then it would just open again. Fearing the worst, like it would need to be re-capped (new capacitors installed) I opened the case to at least give it a quick visual inspection to see if there was anything that could be easily fixed.
I took the RF shielding off the top of the CD drive and then removed the screws that hold the PCB in place behind the disc tray.
I immediately noticed that there is a switch/actuator that when the disc tray closes far enough, the switch should trigger that it can stop moving, it’s gone far enough.
I’m not sure what the exact terminology is here but it looks like there is a plunger/actuator that when the disc tray moves back, will be pushed in when it hits a metal tab at the back of the CD drive. This triggers the 3DO that the disc tray is closed. If the actuator is not fully depressed against the metal tab it will cycle the tray to open again and will be stuck in that state, no matter how many times you press the close Open/Close button.
With the disc tray going as far back as it could and the actuator not fully depressing to signal to the 3DO that the disc tray is closed I thought that I’d grab some pliers and gently pull the metal tab that the actuator strikes forward towards the front of the 3DO. I only moved it a very subtle amount for fear of breaking the metal tab off.
That did the trick! With just a small movement forward on the metal tab it was enough of a distance for the actuator to close enough to signal to the 3DO that the disc tray was closed. Discs now read flawlessly and loading and unloading of CD-ROMs goes without a hitch.