I'm not sure were I first saw the information but its out there somewhere. If the clock tends to work when it gets warmer then I could almost say for sure that its the capacitors. I fixed both my small clocks by changing the capacitors. The 2nd one went a lot smoother because I had done one already. I'm certainly not suggesting this repair just stating what I did. It does require de-soldering and soldering. The leakage of a capacitor would best be measured out of the circuit applying the correct voltage and measuring the current which would typically be in the uA range.