blank screen after Nvidia install

I am referring to this answer from my other answers. I had a login loop issue as mentioned here. It seems you are also encountering a different issue due to nvidia drivers.

First uninstall the currently installed NVIDIA drivers.Boot the computer, when the GRUB menu appears ...

Highlight the Ubuntu menu entry and press the E key.Add nouveau.modeset=0 to the end of the linux line. Press F10 to boot the Ubuntu operating system.

When the login screen appears press Ctrl + Alt + F1 .Enter your user name and the password, then execute :

sudo apt-get purge nvidia*  
sudo reboot 

Now install the latest official stable NVIDIA drivers.Boot the computer, when the GRUB menu appears ...

Highlight the Ubuntu menu entry and press the E key.Add nouveau.modeset=0 to the end of the linux line. Press F10 to boot the Ubuntu operating system.

When the login screen appears press Ctrl + Alt + F1. Enter your user name and the password, then execute :

sudo add-apt-repository ppa:graphics-drivers/ppa
sudo apt-get update
sudo apt-get install nvidia-361
sudo reboot

Note : Maybe it is explicitly necessary to select the NVIDIA adapter in BIOS.

In case you have installed the nvidia driver from their site then uninstall it as per that instructions.Uninstall that driver by running, as root, sh ./NVIDIA-Linux-x86_64-361.28.run and follow the on screen instructions.

Note : The solution I have provide has been tested on Ubuntu 14.04 LTS and Ubuntu 15.10 for two GPUs. Mine HP Laptop has Nvidia GTX 950M graphics card. While HP Desktop has Nvidia 610.

Screen Blanks/Monitor Turns Off

Using a laptop with a GeForce Go card, or connecting the sole display via DVI on a dual-head system sometimes results in the screen not receiving a picture. This is caused by the driver outputting video to the VGA port on the graphics card, instead of DVI.

The usual hint that you have this problem is when you hear the startup sound but nothing appears on the screen. If you do not hear any sound, you are more than likely experiencing unrelated problems.

This is a bug about displays on digital outputs being blank when using NVIDIA driver, and can be resolved by editing your /etc/X11/xorg.conf:

• Switch to the console by using CTRL+ALT+F1, or reboot and select recovery mode from the GRUB menu.
• Open and edit xorg.conf like this: sudo nano /etc/X11/xorg.conf.
• Find the line that says: Section "Screen"
• Insert a new line that says Option "UseDisplayDevice" "DFP".
• Save the file by pressing CTRL+x and confirming to save. If you had to restart into recovery mode, type reboot, otherwise restart your display using sudo /etc/init.d/gdm restart.

for more see here [Nvidia-ubuntu]