I don't know if it related to your issue. But i had an HP Pavillion Laptop from 2005 who started to have strange behavior . He started to not power on everytime , sometimes it powered up , then the last day not , i had to wait few days and it powered up. The delay between the time i was able to power it increased with time until the moment it never power up again. I thought it was a problem with my power button. I bring the laptop to repair . And the guy check and say me nothing seemed to be wrong with power supply or button. But he just clear a persistant ram and the PC worked again. I got back the PC and it worked normally for 2 weeks.. and then started to have the same problem... And at that moment , i just thought about planned obsolescence. what i did , when i was able to start the PC , i went directly in the BIOS and changed the date . I went 10 years back. We were in 2016 , i set the date backto 2006. And after that , the PC worked again normally. The problem never occurs again. the PC worked till 2019 where it died but due to the graphic card.