Hi NHAE,

Thanks for posting.  Apologies that your system is not performing as expected.

Here is information you may find helpful:

How to Troubleshoot Display or Video Issues on Dell Laptop LCD Panel

If you still require assistance and the system is under warranty, you may contact me privately. Be sure to include your personal information (name, address, telephone, email) and your computer's service tag number in your message. Thanks.

If there is no warranty, then you could contact our Out of Warranty team to get a quote for a paid service request. 

Were you able to do a systems diagnostics to check for a hardware issue?  Please run Dell SupportAssist paying particular attention to the video tests.  Make a note of any error messages encountered and post back.  If there are none, then this may be a software or driver issue.

Hi

Thanks for your reply, I ran the Dell SupportAssist, it said everything was OK.

Thanks again