|... oh dear does'nt sound like an update issue problem now!|
... depending on how old the machine is it might be worth popping in a new cmos battery (watch type) you should be able to see it on the motherboard battery should be replaced @ least 5 years
... then see if you can enter your bios by tapping the relevant key(s) @ bootup.
... you should see some sort of post on the (good(?) monitor.
... Posting is provided "AS IS" with no warranties