17 R4 P31E, keeps rebooting

I got this laptop in 2018. It has been running smoothly until a couple of months.

first it stated with the laptop kept rebooting again and agin. I went into safe mode and changed its start up behaviour by disabling Windows Hello. After that it worked fine but sometimes it would keep rebooting. But for that i would go into safe mode and restart the laptop and then it would work fine. 

Once during startup i got a window that stated “Please select blocks you want to recover
Recover BIOS
Reset BIOS settings to default
Rollback BIOS”

I think i selected Recover BIOS option and then it sorted itself out. 
but after a week or so, i turned on the laptop and it would try to turn on but i could hear a small click as if it kept loosing power. Then it would start giving out beeps. First 3 consecutive, then 2 then 1 and then music would play.

I took my laptop to the shop for repair they cleaned it and i also got the battery finally changed because it was swollen(btw the laptop battery stopped working about a 1-1.5 year year after i got it, the laptop had to be constantly plugged-in)

the guy at the shop said that there is a problem with the cable connecting to the screen but i don't think that true because if this were true the laptop screen wouldn’t even turn on.
i also reinstalled the windows 2 days ago. It was working fine after that. I installed some of the software i needed. But after i selected the option of install updates and restart, it keeps rebooting again and again.

i don't know what to do now. Someone please help