It started with i crash my pc tower gently and very ligtly.. The monitor lost the signal black screen and i restarted pc and it came back. The other Day during Windows suddenly lost signal again. I restarted pc no luck after a few restart it came back and gone after 20 min permanlty Pc running, its POSTING, it also can log on Windows (i can hear Windows sounds) usb ports hdd etc everyting working no luck signal. I tried: Reseat cpu, ram, gpu. I replaced psu I clean all computer reapply thermal paste Due to using old vga changed my adapter (tried 5 adapter) Changed vga cable Unplug everthing like sata cables etc. Clearing cmos. For me now there is 3 suspect: -Graphics card led on+power led(ı faced grapichs card error before its 1.5 year old never gave me error or artifacts or drops) -pci express slot. (ıts led on) -monitor I would ask: Grapich card has zero db feature so it fans only run when it reach specifi temp BUT does it suppoese to spin at the start UP i mean during post for about 1-2 second i. Like self test i remember like that? Does it worth to try rebuild outside of case? Lastly dead cmos battery can do this even you post but no signal?