ok, first things first, the support page link for your PC, for future reference..
have you recently had to power down the PC when you did have a video signal with the power button or anything like that? users do that sometimes when the system gets snagged...
the first step i would take is getting into safe mode...it is under boot options...and from there check the device manager for discrepancies
i think with HP OEM units, to get into boot options---safe mode is during initial power up immediately and repeatedly tapping the F8 key. To get into BIOS it is the ESC key.
anyway, if you can get into boot options ----safe mode with networking and you have display in that mode then there is a chipset/motherboard driver update that may need to be done if you are using the integrated motherboard video..
also, are there any POST beeps you are getting during the initial power up?
Edited by synergy513, 13 December 2015 - 03:09 AM.