I did replace a 2688 module in my gw-530 g-shock for a 2687 (EU model), and now neither alarm or beep sounds are working.
After some research, I measured the voltage on the small spring that is in contact with the ceramic (beeper) on the back of the watch, and I have about 1.5V when activating alarm. On my other watch (where the module comes from), I measured only 0.4V, and this one works fine.
Anyone an idea?
I tried resetting the module, but no sound to hear.