Alienware alpha flashes yellow light, no booting

The alien head on the front of the machine is supposed to be blue light when it boots normally. But sometimes it  flashes in yellow and can't boot. The screen appears as "no signal". I have bought this device since the summer in 2015. I've got this problem with it many times. It used to be solved by unplugging the charger and retrying booting after a while.

However, 3 days ago, it keeps flashing yellow light when I pressed the alien head, no matter how many times I tried. No booting any more. The day before, it was fine.

A video on Youtube provides a few steps, which includes holing the alien head for 1 minute, unplugging the CMOS battery and waiting, etc.(www.youtube.com/watch. I followed that and yes, the blue light came back for a few seconds before it turned back to the "yellow blinking", still no booting.

I've seen someone else post the same problem on the community 2 years ago but no Dell employee came to answer. I posted my problem on Dell's facebook page and got no response. Is this a defect of the design of this type of device that may expose Dell's terrible carelessness and irresponsibility?