Update 10/27: A few readers have pointed out to me that it's likely a bad capacitor, which cap it is, and how to test that and/or fix it!
When troubleshooting old electronics, rule #1 is "check the caps". Electrolytic capacitors are the most common failure item in solid-state devices. This alarm clock predates the infamous capacitor plague but the finite and somewhat short lifespan of electrolytics has been known since their invention.
When troubleshooting old electronics, rule #1 is "check the caps". Electrolytic capacitors are the most common failure item in solid-state devices. This alarm clock predates the infamous capacitor plague but the finite and somewhat short lifespan of electrolytics has been known since their invention.