18 Oct 2015, 21:08
Before buying a new module, original or replacement type, spend the money, less than $1.00, to purchase a new quartz crystal. Classic sign of the oscillator not working are random digits showing, like yours, upon battery installation. Digits displayed upon battery installation with no other functions working is NOT normally a sign of static damage or a "very bad sign" that the chip is damaged but most likely due to the internal logic not being reset to the design default state when power is applied. Every function of the watch depends upon the quartz oscillator being operational including the internal logic reset circuitry, button functions etc. The quartz crystals of the '70 vintage were very susceptible to schock, i.e., like dropping the watch on to the floor while putting it on or removing it from ones wrist. Static damage to the metal gate type of CMOS chips used in these watches is rare. They had pretty "robust" input protection circuitry built in. I have personnely discharged in excess of 4000 volts directly into the input of this type of metal gate CMOS chips without damage. If you try a new quartz crystal and the module comes alive, and you also want the original Motorola quartz crystals which were used in this era watch module, let me know as I have some in my stock.