I have a Dell 15r SE (7520) and have noticed a strange problem with it. I have connected an old Dell E176FP monitor to it via the VGA port, which is the only connection option the monitor has available. At any time when the monitor is connected and the computer is either off, sleeping, or the internal display has timed out and turned off, the external monitor instead of going to sleep and showing an amber power light, stays green and gives the disconnected message onscreen, along with a test pattern. The problem is not the monitor because on a desktop or several other dell laptops it goes to sleep normally, showing the amber power light. I find this issue irritating because the test pattern will stay on the external monitor forever and causes it to never turn off.
Does anyone know if this is a "feature" of the laptop? or is there something I can do to fix it?
The monitor should go to amber power light state when the laptop is in OFF state or in the sleep mode. As you have informed that this does not replicate on the Desktops or other Dell laptops, I would like you to connect a different monitor to the Dell Inspiron 15R SE and check if you are getting amber light or No signal message on the different monitor.
Sorry it has taken me so long to respond, I had to get my hands on another monitor. I did get another Dell monitor with VGA input, and it has the same problem, when the internal screen is powered off the external monitor will go to the test screen and never turn off.