Only while plugged in, the Laptop screen(goes black) doesn't respond after idle screen timeout.

Ok I found one file that causes a BSOD, it called ETD.sys from your mini dump file. 

To read more about ETD.sys please follow the link don't download anything there, I send to you to just get an information about the file https://www.file.net/process/etd.sys.html

KMODE_EXCEPTION_NOT_HANDLED ETD.sys+4e9d6 (relate to  mouse pad) (is possible your black screen is caused by this ETD.sys) Get an external mouse ready in case your mouse pad refuses to work after the modification we are going to do. Here is what you are going to do.

open command prompt as admin

cd\  (hit enter key on your keyboard)

C:>

C:>cd windows\system32\drivers (hit enter key)

C:\Windows\System32\drivers> ren etd.sys etd.sys.old     (hit enter key) (ren command is to  Renames a file or files)

Then reboot your laptop

Work with your computer as you did and see if the blank screen is still there, we close the laptop lid when we use an external monitor connected to the laptop ports (vga, hdmi,dvi). You can still close it to see if it freezes. Leave a feedback

Hey, I tried this after I reinstalled factory version drivers of Elan touchpad as I told you before that I was using unofficial drivers which u said was the reason for BSOD. but now after reinstalling official HP drivers and running those commands it showed the ETD.sys file is not present(I think that file was of unofficial drivers). So I tried closing the Lid again and the BlackSOD happened again I had to hard reboot my laptop. So I'm sharing the dump files again to see if you can get any other error msgs.

Link - https://1drv.ms/u/s!AtuSyEHlaqZvlDiKS9wKLjr6DU5z?e=K5Estc

And this is even happening after connecting the HDMI cable. One thing I observed that when I closed the lid jus enough for the screen to turn off and while the HDMI cable connected I tried to move the mouse with touchpad and tapping keys and they didn't respond after closing the lid but when I opened the lid they worked only External mouse worked at that time.

Hi 

It is the same file (ETD.sys) that causes the BSOD.  Why don't you just completely uninstall it reboot your laptop  and see how your laptop reacts without that apps (Elan touchpad) then we will know if it is not the responsible of your BSOD.

I think you found the same issue because the dump files never changed. They are the same file as I checked the timestamp

And I tried uninstalling that Elan app from settings>apps and also from device mgr but after reboot they get installed again. The thing is I need that touch pad app because without that I cannot use any gesture on touch-pad as I use it most of the times.

I really don't think that issue lies in these drivers but in Intel MEI drivers because I've seen that blk screen only happens on battery but after checking the option "Allow computer to turn of this device" in pwr mgmt tab of that driver the issue occurs even while on battery power, as for now I've left it unchecked that's why its not happening on battery.

And I saw this error in Event viewer sys tab is this OK or this needs attention?

MEIx64:-Intel(R) Management Engine Interface driver has failed to perform handshake with the Firmware.

Open minidump folder c:\windows\minidump\ then delete all the files then wait to get a new file and send it on your onedrive.

Can you use this method  "It Worked" to downgrade your bios when you get there find "it worked" the second last message.

Is it really safe? because that method says to install the latest version not downgrade, and above that this is of Asus laptops and I have HP just to do a check I've seen there is no such folder as winflash in the file directory specified in that page and they said this winflash is preloaded but in mine it's not. As HP's community employee told me that if there are any security improvements to BIOS update then the BIOS downgrade is not possible and I've seen the change log of my current BIOS update file and it showed "Security improvements" only, that's why I've lost all hopes of this getting fixed until HP release another BIOS update and if that update didn't fix this I'll sell my laptop.