Im planning to buy Laptop atm, alot of the laptops that is on my budget range are soldered RAMs into the board, some do have soldered RAM onboard but has extra DIMM slot to put another RAM stick

The question is…

What would happen if a Soldered RAM fails but the Laptop have an extra RAM slot. Will the laptop still works even the soldered RAM fails but you have another RAM stick on the modular slot/DIMM?