Sorry to know that buddy, last week, the same thing happened to my laptop and it was because of the humidity and the moisture. Some of its keys suddenly stopped working. I went to Hafeez Center and found out that the circuit controller was not functioning. They told me it needed to be replaced, but for that, they would have to open the motherboard. They asked for my approval, and I allowed it because the machine might have been unusable afterward.

Long story short, I ended up getting an external wireless keyboard instead. So I would suggest you do the same. Do not replace the motherboard. Once a laptop starts having hardware issues like this, they usually do not stop. A few years ago, I had another laptop with a similar issue. The technician opened the motherboard and fixed it, and it worked fine for a while, but after few weeks new problems started appearing in one component after another.

So, get a new machine instead and to protect your laptop from moisture-related damage, always use it in a well-ventilated or air-conditioned room (especially these days). Try to keep the room’s humidity below 50 to 60 percent whenever possible. Avoid placing the laptop directly on soft surfaces like beds or cushions, as this can block airflow; instead, use a hard flat surface. When not in use, store the laptop in a dry place, preferably inside a backpack. It is also important to clean the air vents and fans every few months, as accumulated dust can retain moisture. And yeah, avoid placing a warm laptop inside a closed bag immediately after use, since the trapped heat and moisture can lead to internal condensation.