31 Oct 2009, 13:05
The button magnets in the P2-3-4 series modules were typically AlNiCo 5, an aluminum-nickel-iron-cobalt alloy that is still an industry standard for many applications. It is one of the best materials for permanent magnets [permanent magnets, as the name implies, do not lose their magnetic strength unless 1. subjected to a very powerfut external magnetic field, or 2. heated above the Curie Point, the temperature at which a magnetic material loses its' magnetic properties...typically, many hundreds of degrees C.]. Mechanical shocks, even such as the thousands of Gs Time Computer tested their modules at, do not affect the strength of such magnets. The switches themselves, though, ARE subject to damage by mechanical shock or powerful external magnetic fields. So, given all that, my guess is that your switch, not the button, is the source of your problem. The leaves are only a few thousandths of an inch apart [.1 to .15 mm], so there is not much tolerance in the relative position of switch-to button. Not only is the separation distance critical, but so is the rotational orientation. So, with all these variables, it was not possible to be certain that one module could be transplanted into another case, with any reasonable expectation that the button response would be acceptable [the reason all such repairs were done at the factory, and why the color-coding of the switches, a not-always-successful attempt to make the parts interchangeable]. The simplest test is, with the module powered, and out of the case, short across the switch [a fine-pointed pair of tweezers are ideal; and do this only if you are properly grounded...any amount of static electricity is the kiss of death for these modules!]. If the date displays, it's the switch, if not, it's likely a break in the circuit deeper in the electronics, and probably not repairable. And beyond having good button response [where the display is activated when the button is about three-quarters of the way to the limit of travel...not a heavy push or a gentle touch], I can't think of any way to be absolutely certain that the module is exactly the same one that was in there when the watch left the factory.