Two days ago, I was hurrying to an exam and had to walk in the rain, resulting to my backpack getting rained on. When I got home, there was a tiny amount of water on the side of my laptop, but it didn't appear to had gotten inside, so after wiping off all the water I tried to power it on. It didn't. The little LED to indicate power didn't light up. There was absolutely no sign off power. I brought it to a small local laptop repair shop, and got it opened. THERE WAS ABSOLUTELY NO SIGN OF WATER or moisture. The guy there told me that I had to get my motherboard replaced. He used a multimeter and it seemed that the AC input was working correctly. A motherboard is expensive, and my laptop is just over a year old. I'm off tomorrow to get a second opinion, because I'm a CS student with projects due soon and I have to get this fixed but I'm also hesitant to spend that much cash if I'm not sure. Could it be the CMOS battery or some other thing I can check before I take the laptop to another technician? I'd really like to have some idea of what went wrong here because if it wasn't the water, could my i5 motherboard be really broken so early into my laptop's life?
Anywhere in your laptop, physical or electrical damage can cause a short circuit. A short circuit will consume all available power, causing your laptop to not turn on. If your power adapter LED comes on when you plug it into the wall, but then goes off when you plug in the laptop, you probably have a short circuit.
Try to pull the battery and unplug the laptop from the external power source. hold the power button down for 3-5 minutes. Plug everything back in to see if that works. if not, your laptop may have a reset button, you'd have to poke it with a pin