Some notice for my fellow G-Shockers. Some shop will try to cheat you when you go for a battery replacement. G-Shock got two main components. The outer rubber casing and the stainless steel watch module inside. In my case, the shopkeeper replaced the stainless steel module with some cheap knockoff while still retaining the original outer rubber casing. Luckily, i test all the buttons before i walk away and i quickly noticed that the function of each buttons have changed.

I pointed out the "discrepancies" and told the man to "fix it".

I knew it because i've open my watch before and examine the innards. No i didn't watch him fix it as he take my watch to the back. But my watch is already 8 years old. It has wears and tears that i can easily identify and it's unique to my watch. Plus all the button feel's just right . So i decided he "fix it" already aka replacing the SS module with the original one. Anyway below are the example of the inside of G-Shock. You can see the outer rubber casing in the background on the table.