Question PC having trouble is it my recertified power supply?

Feb 4, 2019
Build is as follows
GTX 1080
I7 7700
Biostar Racing Z270GT6 motherboard
16gb ddr4 ram
corsair 750 watt bronze recertified power supply

I upgraded a couple months ago and cheaped out on a recertified power supply, well the other day im gaming in the morning turn off my pc normally through windows, come back in a few hours too boot up and computer starts but will not display too either of my monitors(Most LEDs on, all fans on all components spinning) so i unplug everything (power cord, hdmi, all cables on the outside) and do a good dedusting still nothing. few days pass and on a whim i press power and it boots up normally i play for a few hours, turn it off & when i attempt to get back on its back to no display. i hear no beeps on start up. The 2 main reasons im thinking it is power supply is 1.its the only refurbished component in the build & 2. some of the leds are not powered anymore and on the day it worked the LEDs did as well. im not very intelligent when it comes to computers and i dont know if anyone could tell me based on this info so thanks for any help