It is easy to check with a multimeter whether the antenna leads are bad, and there are readilly available on-line replacements. Videos for your model disassembly are available on You-Tube if needed. To me it sounds like a software/driver issue though. I would look at MSI's support page for not only drivers but a BIOS update since you aren't using the installed OS and a BIOS update might be what you need. When you disassemble the critter look for any spots where the lead(s) may have been pinched or crimped if the device was worked on before the lead routing may have been wrongly performed, otherwise it's unlikely they are the problem. You say you replaced it with a known working one so, maybe you'll find a problem with the antenna(e) or leads. My bet is on OS and Driver issues. Check the BIOS version and MSI's support page for a possible fix. Good Luck.