This one was a Sound Design AM/FM clock radio with a flip clock that no longer advanced on its own. The radio still worked, and the cabinet was in really nice shape, so the problem was isolated to the clock mechanism rather than the whole unit being dead.
I picked it up after seeing someone ask for help with it, and it also brought back a memory of a similar clock radio I had messed up as a kid. Before opening it up, I confirmed that the radio section still played. The set had tuning and volume on the sides, alarm and clock set controls, a sleep timer, and even external speaker connections.
Getting inside took a little care. The side knobs were on very tight, so I eased them off gently with a screwdriver and my fingers rather than forcing anything and risking broken plastic. Once the cover was off, the clock mechanism was easy to see, along with the motor that drove it.
Turning the clock and alarm controls by hand helped show how everything was supposed to move. There were also two microswitches tied into the alarm function. The clock motor was a Copal GC-1341 120V AC motor, and it was wired directly to the incoming AC, so I was careful while checking it with power applied.
Here is what I found: the motor wasn’t fully dead. With the unit plugged in, I gave the little speed indicator on the motor a slight spin, and that was enough to get it going. Once it started, the clock digits advanced normally, which narrowed the problem down to the motor sticking rather than a broken gear train or a missing belt.
I removed the motor and tried the usual first step, adding a small amount of fine lubricant to the shaft and working it in by rotating the motor a few times. That wasn’t enough. After reassembly, it still wouldn’t reliably start on its own.
So I went ahead and took a more aggressive cleaning approach. I used isopropyl alcohol on the half of the motor where it was binding and spun it several times to loosen things up. That did free it up, although it also removed some of the painted timing marks on the speed indicator because they weren’t a sticker like I first thought.
Once I put it back together and plugged it in, the motor spun up right away without needing any help. I cleaned up the radio, returned it, and the clock was working again.
— Aaron
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Timestamps
00:00 – First Look
03:22 – Diagnosis
08:11 – Repair