Windows 11 PC will not start up even form flash drive

To clarify yes the SSD is the windows drive and I have 2 HDD data drives. Originally the noise I could hear sounded like a HDD trying to spin up and failing rather than the clicking of a fan. Removing cleaning and replacing the RAM has cured that and now starts up and all fans spinning quietly. The computer is not connected to a speaker but I assume the beeping mention comes from the motherboard and i am not hearing anything. The monitors not responding is not because of the wrong connections as they were already connected as when it was working.

What I have done is
1. Replaced the button battery
2. I have 2 sticks of RAM so only 1 installed
3. Graphics card is removed and onboard HDMI port connected to monitor

with both single sets of RAM I would describe the behaviour as intermittent. The fans start up then after a few seconds cut out and try to restart like I had before. Put both sticks in and wont start at all. Now completely dead. Lights on the MB, but no action from fans. Seems like dead chicken?