Second monitor connected to Inspiron laptop flashes randomly

Hi,

This is frustrating. I am using a Dell Inspiron 15 laptop connected to an old BenQ Monitor. The monitor is not HDMI, its VGA. I am using an HDMI to VGA adapter, connecting my laptops HDMI out to the monitors VGA in. My second monitor goes off (no display/signal) and on randomly. This goes on several times when am using the laptop, but apparently for no reason (no heavy graphics works, no plugging or unplugging of usb, etc.) I started facing this problem since i last updated my graphics card, NVidia GeForce GT 750M. I updated it and installed GeForce GameReady drivers and ever since am having this problem. 

Can someone please help me out. I tried updating the drivers, checked the cables, everything i could think of. As i  am writing this my monitor is going off and on every minute.