HP Envy x360 15u400 Screen/Monitor just stopped working

[RiverCityTiger]

My son booted up his computer yesterday and when he was entering his password to enter Windows the keystrokes were not registering on the Password space and then the monitor just went blank.  The computer will turn on (power button and fan running) but nothing at all on the monitor.  I have tried a hard reset, external monitor and BIOS boot and nothing has worked.

Any thoughts or suggestions?

RCT

[MKazi]

@RiverCityTiger

Thanks for reaching out to us on HP Support Forums. 🙂 I came across your post and would like to help.

I understand that you have an HP ENVY 15-u400 x360 Convertible PC and the screen went blank while working on it. Since then there is no display and you see that the power button light is on and the fan is running.You have performed a hard reset, and tried to boot into BIOS and also have attached an external screen but nothing works. Fabulous analysis. Spectacular diagnosis of the issue before posting. Kudos to you for that.

I would like to know the following information to assist you better:

• Were any hardware changes made to the laptop?
• Did any software updates happen recently?
• Does the laptop overheat?

Meanwhile, Let's try to recover/rollback the BIOS by following the below steps as described in this link.

If the monitor screen continues to remain blank then the evidence points towards an internal hardware issue. In that case, I suggest you to contact HP phone support to explore the hardware service options for your laptop.