I decided to disassemble my two N900 because really at the end to compare both found the of made in finland (2101 version) is faster and maintains a low temperature in the CPU that it is made in korea (version 2104). This device bought on Ebay on your motherboard contains components from Japan and the other device made ​​in Korea has components from VIETNAM . I also checked if there were any USB port repair, apparently nothing. Upload photos for an expert opinion.
Because I found some small differences indicated there.