Replacing the motherboard is technically an upgrade, but rarely worth it.

Yes, you can upgrade a laptop with soldered RAM by swapping the whole motherboard for one with more memory. That’s how it works in practice.

The issue is cost and availability. A replacement motherboard often costs as much as the laptop itself, especially if you’re buying new old stock or a used board. And you’re stuck with whatever that specific model offers — no picking RAM speeds or capacities beyond what the board was built with. On top of that, the swap is fiddly. Thermal paste, connectors, and potential compatibility issues with your specific chassis or BIOS version make it a real project.

Unless you’re getting the motherboard for free or near-free and have the skills to swap it, you’re better off just buying a different laptop with the RAM you need. Soldered RAM was never meant to be user-serviceable, and this “upgrade” path is more of a workaround than a solution.