RE: 1 high sounded and 7 low sounded beeps on POST in Dell Inspiron 15 series Laptop
What is the exact system model? Is there any damage on the system?
7 beeps is a CPU failure - which ideally indicates a faulty motherboard and the same needs to be replaced - see this chart for info about beep codes - http://dell.to/1IuETMX
If the system is under warranty, Please click my DELL-username and write me a private conversation with the service tag and your contact details(Name and Email). If there is no warranty, then you could contact our team to get a quote for a paid service call - http://dell.to/1vnT6CQ
If you have important data you need to recover, then download the service manual - http://dell.to/1n3X2po - enter the service tag and download the service manual and remove the HDD from the system - get an external caddy for the HDD from a local store and plug it into the caddy and use it as an external HDD when connected to another system and save any data you need from there.