DIAGNOSIS AND REPAIR
Although all functions work properly: the digits on the digital LCD display are very clear, even the light is nice and bright, but the watch does not make any sounds. What’s going on ?
It may happen that your watch does not make any sound despite pressing buttons, especially in stopwatch mode. What’s worse, although the watch seems to be quite functional, the alarm does not work either. What could be causing this?
* Now ask yourself which of the following 2 options applies to you. This will make it much easier to diagnose the cause of the lack of sound in your watch.
- It’s possible that you bought this watch or got it from someone and the watch didn’t make any sound from the beginning.
- It is also possible that the watch made sounds, but after replacing the battery with a new one, it turned out that your Citizen Watch was speechless.
* If option 2 applies to you, see point 1 below.
* If option 1 applies to you, please consider points 1, 2 and 3 below.
One thing is certain, if you found yourself on this post, it means that one of the three options described below has happened to you.
3 main reasons for no sound :
- 1. You have lost the buzzer contact spring touching the piezoelectric.
- 2. The power cell strap has no electrical contact with the back of the watch.
- 3. Some electronic component inside the watch is damaged *Emergency option
Now we will discuss all three causes of the lack of sound here, one by one:
Reason No. 1 : You have lost the buzzer contact spring touching the piezoelectric.
If the watch was making sounds and now it is silent, it almost 100% means that you have lost the microscopic buzzer contact spring (or maybe it was never there) connecting the watch mechanism with the buzzer. Check if it is there… The spring should be located in a small hole, above the power cell. If you look at this hole: it is marked on the green plastic cover of the unit as “COIL SPRING”
Reason No. 2 : The power cell strap has no electrical contact with the back of the watch.
Also check whether the power cell strap “BATTERY CONNECTOR”, or rather its small protrusion, protrudes sufficiently, as in the photo below.
* On newer models of this watch, the power cell strap lugs may look slightly different, i.e., they may be positioned in the center of the power cell strap.
What you should do now is open your watch. If you do not know how to do this so as not to damage the watch, please refer to the “How to replace the battery” section. If you have done this many times and know how to open a watch, or maybe even an open one, you can skip that section …
Now check if there is a microscopic spring sticking out of the device cover. The spring should extend above the green device cover by approximately 2 mm * 0.078 inch. Make sure all electrical connections to the buzzer are operational. If necessary, you can slightly bend the protrusion of the power cell belt or even stretch the spring a bit …
The photo below shows a piezoelectric buzzer: the place where the contact spring of the buzzer should touch and the place where the protrusion of the power cell strap should touch, so that the watch can make sounds. As you might have guessed, both of these connections need to carry an electrical signal, so you already know how important they are …
Reason No. 3 : Some electronic component inside the watch is damaged.
It is possible that there has been no sound in the watch forever. In this condition it came into your hands. If you have checked the spring and electrical connections to the buzzer and you think they are OK and there is still no sound, then the cause is most likely completely different – inside the watch. This is a worse case scenario, but it can also be fixed. Look…
The picture below shows the electronic circuit diagram of the watch, specifically the chip and all its external components. The buzzer section is marked with a blue frame. There is the buzzer itself and all the elements responsible for its proper operation. To produce sounds correctly, the buzzer needs not only a direct signal from the processor, but also these elements.
As you can see there is “Buzzer transistor, Buzzer resistance, Buzzer condenser, Buzzer boosting coil and Piezoelectric element”. We are only interested in “Buzzer transistor and Buzzer boosting coil”.
Why only them? Because these two elements in extreme cases can overheat and burn out. The remaining elements, i.e. the resistor, capacitor and the piezzo buzzer itself, practically do not break down.
In the diagram below, the potentially interesting transistor and coil are marked in red and the buzzer is marked in green.
- For a Boosting coil, the resistance should be less than infinity. Because when it burns out, the coil stops conducting electricity. It is similar in the case of a Transistor.
- In the case of a resistor and a capacitor, the opposite is true. These elements most often start short-circuiting when damaged. So it is also easy to measure the resistance of these elements with an ohmmeter.
Where can I get replacements for these items? Most often, this is done by transferring components from other damaged and unused watches.
- First of all: we do not always know the values/parameters of these elements *especially after they are damaged, it is difficult to determine.
- Secondly: the characteristics of these particular elements are often surprisingly similar or even identical in the case of even different models and brands of watches.
- Thirdly: It is difficult to find even such a miniature coil in the store.