Laptops Hp probook 640 g8 booting issue

manohar5321

Forerunner
Hey folks , I just bought a used hp probook from a member.
Upon turning it on it worked. I tested the routine things like wifi and bluetooth and speakers and stuff and turned it off.

After a while I tried turning it on again and all I get is the caps lock led blinking 7 times, I haven't installed anything nor changed any settings even . It was freshly installed windows 11. The display is completely blank not even showing the hp logo

I looked up on the internet and it mentioned that it could be a bad bios , so I followed the usb bios recovery but it didn't work. I tried to see if the one of the ram was bad , that didn't work.
The seller asked me to disconnect the battery and power adapter , wait for an hour and then try connecting the battery again to see if it resets the system but that didn't work. But after doing this the power led is always on and doesn't turn off at all.

Any clues as what is happening