If your computer doesn't turn on it is probably the power cable. The damage to the power cable is not always visible from the outside. To fix this you need to:
Unplug the power cable (its usually the thickest cable)
Find out which company manufactured your device and what model your computer is. For example: Manufacturer = HP Model = HP ENVY 795
Go to the manufacturers website and find the search bar
Enter the model name of your computer and then put 'power cable' at the end like the image underneath this text
Order the cable
When the cable arrives just plug it into a plug socket and into the computer
If you are still struggling you can contact us at 'redstonewirestech@gmail.com' or at '07871 000773'.