I have a Dell inspiron 7746, comes with intel HD 5500 integrated graphics and Nvidia 845M. After I had to change my hard drive, I recovered my windows 8 (originally on the laptop) and then reinstalled windows 10 home (build 1079).
ever since I replaced the hard drive I can not get the HDMI port to output anything. no external monitor works. I tried different laptop and the monitors are fine.
Since then I have updated my BIOS, updated the graphic drivers, uninstalled and reinstalled the drivers. I can't think of anything else. The diagnostics test do not show any thing wrong with my laptop. all other ports and internal parts work just fine. I can't tell what could have gone wrong. I am suspicious that this is software related problem but I cant be sure. can anyone help me with this?
Just to be sure, have you updated the drivers for both the Intel and NVIDIA GPUs rather than just one or the other?
And just as general notes, if your system has already claimed a license for Windows 10, you no longer ever have to go back to Windows 8 to run the upgrade to Windows 10. You can instead perform a clean install of Windows 10 directly and it will still activate. Even easier would have been for you to simply clone your previous drive onto the new drive so you could have avoided the reinstall work entirely, though. If the previous drive died unexpectedly, then if you'd been capturing image backups on a regular basis, you could have restored that backup onto the new drive to achieve essentially the same result. Might be worth considering doing that going forward if you're not already.