Wireless drivers for Asus laptop

I have an ASUS X551M laptop that I use as a secondary/backup computer and over the last 2-3 months, it has started dropping the wireless connection. I replaced the original Atheros AR9485 card with an Intel AC-3160 a month ago, thinking this might solve the problem. It gave me better signal (I've always had bad signal problems with Atheros), but the connection still disappears after an hour or so. It will be working fine, and then I will try to access a webpage, or connect to my IRC client, and the signal indicator in the system tray will show full bars, whatever page or program I'm using will fail to connect or show no connection, and I get the little yellow alert triangle on the wireless icon in the system tray. I can get it working again if I go into Device Manager to disable/re-enable wireless network adapter. There is no yellow alert triangle on the icon for the wireless card in Device Manager, and it says the device is working properly, even though I can't access the internet and the triangle appears on the signal icon in the system tray.

The problem is the same, and is 'fixed' in the same way, if I use the original Atheros card. Connecting to the modem/router via ethernet does not present any issues. I would like to find out if it is a hardware issue so I can send it to get fixed on my protection plan. If it's something I can do, I'd rather take care of it myself.