Lenovo Windows 8 low Wi-Fi signal?

I have a Lenovo Ideapad N580. And it was working fine until a few weeks ago. My Wi-Fi signal is only 3-1 bars, but I'm only 15 feet away from the router. My mother's and sister laptops are connecting fine and there and my smart phone is fine, and my sister is further away, so it's my laptop.

I did two factory resets but to no avail. I took the back off and unplugged the two Wi-Fi cords, u plugged there called antanas I may be wrong. But I unplugged and plugged them back in, still low connection. They aren't tangled or lose there fine.

I can connect to the Wi-Fi but it's just a low signal? When I plug Ethernet is faster. But no one want to do that. I can be right next to the router but only have 4 bars max… I don't gave my warranty anymore so can't send it to Lenovo. Is there away I can solve this at home? I'm a little tech-savvy.

Three things come to mind:
1. What happened in the last few weeks that may be affecting your Wi-Fi reception? Dropped laptop? Wet laptop? Kids played w/laptop? Buddy borrowed it? What?

2. Be sure to visit the Lenovo support forums. Search their records to see if any other Lenovo owners are having (or had) the same issue.

3. While we await more info from you… Also visit the Lenovo Support site and see if there's a newer Wi-Fi driver for your model laptop and version of Windows.