Soldered RAM is soldered. No hidden sockets.

No. Not in any consumer device I’ve seen or heard of from a reliable source.

If a manufacturer wanted you to upgrade the RAM, they would use a standard SODIMM or CAMM socket that’s clearly accessible. Soldering is cheaper and saves space. Hiding a socket under a heat shield would add cost, complexity, and extra heat for no good reason.

Some modular laptops (Framework, some older Clevos) use socketed RAM, but that’s explicitly designed to be user-replaceable. That’s the opposite of soldering it. The idea that a company would solder the chips and put a hidden socket underneath is a fever dream from a forum post that got shared too many times.

If you see RAM chips on a motherboard—especially tiny black rectangles next to the CPU—assume they’re soldered. Check the spec sheet from the manufacturer. If it says “soldered,” it’s soldered.