Inspiron N5110 Windows 10 Update Black Screen

I have a Dell Inspiron N5110 laptop.  I purchased it mid 2011 and although it is 5 years old, it has been an extremely reliable basic home computer. After relentless prompting from Microsoft, on 29 July I finally hit the button and upgraded from Windows 7 Home Premium (64 bit) to Windows 10.  While I know the upgrade was completed, unfortunately now I can’t successfully use the laptop and am trying to work out what to do next.  The current status is:

• Laptop display - a fully black screen (no cursor). This means I get no visual prompts using just the laptop when I turn it on or shut down power to the machine. 
• External Monitor display - eventually fully black screen with cursor, but able to see / access log on and log off screens. 

Using the VGA port to connect the laptop to the monitor, when I first turn on the laptop, on the monitor I get the standard Dell and Windows 10 login information before it finally turns black (with visible cursor).  The laptop screen stays fully black.  Therefore, using the external monitor display, I was able to complete the Windows 10 installation (accept agreement), and using ‘’control, alt, delete’’ I can do a normal shut down process.

Using the HDMI port to connect the monitor, it is more or less the same as for the VGA port above, but it takes a few seconds more before the monitor screen finally turns black. The monitor screen display also flickers on and off before it finally rests and turns to fully black (with visible cursor). Therefore, I have seen that everything is as it was before the Win 10 upgrade, and I have been able to open File Explorer and see that my existing data files are still intact.

Any advice on my next steps?  Reading through the troubleshooting, it looks like to stay with Win 10 I have to update my Basic Input Output System (BIOS).  Is this correct?  And if so, can I do it from where I am now, i.e. without a full reinstallation?  Is there a step-by-step guide (video) as to how I do this?  Alternatively, do I need to revert back, and stay with Win 7?  And is there any guidance on how to do this from where I am now?

I would really appreciate any advice.

Thanks