A Johnny Mnemonic machine we’d bought was having movement issues with the magnetic hand in the left rear of the playfield. It didn’t want to move left to right. The gearboxes were noisy, too.
Here’s how you clean the gearbox and solve the noise problems.
Here’s the problem with our left-to-right movement. The X-nut had been wearing unevenly as it traveled along the threaded rod, causing the hand to hang up.