Why has the backlight stopped working?

I've only had my laptop for a few months. I haven't dropped it and I haven't spilled anything on it. The other day I opened it up and the screen was black. I figured out that it's just the backlight. It still functions I just can't see the screen.

I took it into an authorized repair place and hey said it's either the motherboard or the charge port. They said they reset the connections but to no avail.

Is his a common issue for this model? Are there any other solutions?