Windows won’t recognize second monitor anymore

hdmimultiple-monitorsvgawindows 8

My second monitor (an HP S2031 monitor) has stopped being recognized by my laptop, a Dell XPS 15 running Windows 8. It has an intel i7 with integrated graphics and a GeForce GT 525M card. Previously it had been working fine using an hdmi cable and a hdmi to vga port adapter but now my laptop will not recognize the monitor at all whether I reboot the computer, disconnect or reconnect the cables, and the monitor doesn't react or detect the computer no matter what I do.

On the control panel/screen resolution, I only see one display, but if I go to the devices bar on the charm bar, it says "Second Screen", and clicking on it allows me to change the projector settings (like windows+p) but if I extend anything then nothing appears on the monitor even if I can move the mouse off screen.

Any ideas on what might be the problem? I'm stumped myself…

Best Answer

I think everything is fine on your laptop, the problem lies in the adapter or monitor.

HDMI uses pure digital signal, while VGA is pure analog. Adapter has to actively convert signal for this to work. It means there's some piece of electronics inside, and electronics sometimes just fail.

It is also possible that your monitor's backlight is dead. More on that later.

First thing to try is to connect another monitor through the same adapter. If it won't work, then you should try it without the adapter. If everything will be back to normal, then it's the adapter. You have at least two cheaper alternatives to buying a new adapter: use VGA-VGA cable or HDMI-DVI adapter. (DVI can carry digital signal and is compatible with HDMI, so you can use passive adapters here)

If another monitor will work through the same adapter or the same monitor won't work with another PC, then it's obviously monitor's fault. But there's a change you won't have to replace it. Take a flashlight and point it at the screen. If you'll see anything, then you can try replacing just the backlight inverter. (those fail sometimes)