We have an S4 timer from '98 which developed some problems over the summer/autumn of last year. Two of these I could live with, as we only use the S4 for capturing manual starts/stops - beeper not beeping and the meter has pretty much unglued itself.
The showstopper is that the C0/C3/C6 inputs are pretty much dead. C0 works once after power on, and never again. The other two don't even do that. Measured the open circuit voltage on these to 2.5V, 0.2V and 0.2V respectively, compared to 4.8V on the stop and intermediate pins.
Does anyone know what might be dead? I'm thinking aged electrolytic capacitors but could be way off. We've already replaced the S4 with a new Timy, but if I could fix the S4 as a project it would be very sweet.