For over six months. It is an intermittent problem that if you rock and jar the laptop, it just may go away for a while. After receiving the machine back from HP for the fourth time in six month. I took the machine to a local HP authorized service center who reproduced all the problems, except a failed CD drive in about 45 minutes. They wrote a report which I emailed to the service case manager. The result was that HP wanted to replace the machine but would not replace it with one that I considered overall an equivalent machine. So I am having them repair the machine with a new motherboard and display.
The HP service center asserted on all the return invoices that the problem could not be reproduced. Yet the local repair center reproduced the problem in a short time and also repeatedly demonstrated it to me.
The problem is that the LCD display connector is seated just underneath the power button. This connector will create the problem you described if you move it (read touch or jar it) and it is not a connector seating problem. Unless HP received a lot of defective LCD displays, the problem is not with the display.
I suggest that you escalate the repair and have the case manager look at the repair center analysis I sent in on case #LUN596.