Hi, I got this Alienware 15  one year ago, everything was fine until today. 

i7 6700hq

980m 

A Strange thing happened in this morning. The notebook somehow can't find the wifi hotspots so I turn off the computer and turn it back on to see if I can fix the issue. Then, the beep sound. Two beep possibly means RAM issue, so I tried to reseat and even replace the RAM, but with no luck. 

Looking for some help, I know the motherboard's memory slots could be the cause, but I wish to hear someone's opinion about how this issue occurs in a sudden with no obvious indication.

One thing I have to mention, I did leave it on sleeping mode a lot, and sometimes I just let it run out of the batteries.