What is the difference between original Gameboys made in China vs being made in Japan?

Well if the words on it are in Russian the device its self was probally puted in by a Russin spy working at the Nintendo factory at the time. According the news there are still Russain spies in The US and in Canada. Yes LCD existed back in 1989 when original gameboy was made. So it was in there since it was firsr being manufactored at the nintendo factory. I have 3 original gameboys and none of the have A small chip like that in them then. So its a one in 1000 orignal gameboys will have a chip in them or or candies putted in them since production.

Japanese manufacturers like Korg, Yamaha, and Roland have some components and products manufactured in China, while some components and manufacturing still occurs in Japan. Theoretically the Country of Origin ("Made in Japan" or "Made in China") is supposed to denote where the product is manufactured, or where the product undergoes the most transformation (e.g. assembly of raw parts made in one country into whole product in a second country).

I would say that China builds products to the standards they are requested.