Boot device not found, no hard drive installed

[Nora29]

Opened my laptop finding black screen with an error says 

Boot device not found 

Tried to diagnosis the hard drive but it shows 

No hard drive installed?

This is strange and it was working properly before two days. 

Need help please ASAP 

Best 

[Echo_Lake]

@Nora29

Thank you for posting on HP Support Community.

Don't worry as I'll be glad to help, I have a few troubleshooting steps we could try to fix the issue:  

Firstly, let's reseat the hard drive and memory.

1. Press and hold the Power button for 5 - 15 seconds to turn off the computer.
2. Disconnect the power cable.
3. If your notebook model features a removable battery, remove the battery.
4. Disconnect and reconnect the internal hard drive and Memory. For instructions, see the Maintenance and Service Guide for your notebook model. Locate these in the User Guides section of your notebook product page on the HP Customer Support website.
5. After connecting the hard drive and reassembling the computer, try to start the computer normally.

If reseating the hard drive and memory does not resolve the problem, try replacing the memory modules. You might also consider contacting support for repair due to a possible RAM or system board failure. HP Support can be reached by clicking on the following link: www.hp.com/contacthp/

Click here: https://support.hp.com/in-en/document/c01443463 to know more 3F0 Boot Device Not Found Error Displays on a Black Screen​​​​​​​.

Please feel free to contact us here anytime you need any further assistance. Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.