Don't buy a dead laptop for its soldered RAM.

No, it’s almost never cost-effective.

Here’s the thing: soldered RAM isn’t designed to be removed. It’s reflowed onto the board with hundreds of tiny balls under each chip. Desoldering them cleanly requires a hot air rework station, steady hands, and experience. One slip and you’ve got a dead chip and a dead donor laptop.

Even if you manage to remove them intact, there’s no guarantee the new laptop’s BIOS or controller will play nice with chips from a different board. Compatibility is a gamble, and the cost of tools or paying someone to do it will blow past the price of just buying the RAM upgrade your laptop actually supports (assuming it’s socketed—if it’s also soldered, you’re stuck anyway).

Your best bet: sell the dead laptop for parts or as-is, then put that money toward the correct RAM or a different machine. This is one of those projects that sounds clever on YouTube but costs you more in the end.