I do not think there are any main computer parts made in the US, and have not been for decades. Way back in the early 1990's, I used to build several different models of computers. One of them featured a motherboard made by a company called Beaver, based out of Oregon. My aunt even worked for them in their Medford office. They folded decades ago. Most people shop by price, not where a computer or the parts are made. And if a motherboard from a US company costs 15% more, most will choose the import. Then they complain a decade later that everything comes from China. Kinda like how nobody realized what they did to Quasar, Zenith, RCA, Curtis-Mathes, Magnavox, Motorola, Sylvania, etc, etc, etc. They kept going to cheaper products that were imported, and eventually no TVs were made in the US. I bet most people never realized the last American TV company was bought out over 20 years ago.
Actually, into the mid 1990's, a lot of the parts in your computers still came from US sources. Memory, CPUs, keyboards, mice, monitors, even the cases. Back then only a few components were generally imported. It is very different today.