Notebook Boot and Lockup

Starting on February 14, 2025, my HP 15 Notebook PC has begun to fail in the booting process. When this first happened, it was able to successfully boot, but the caps lock LED blinked once every 3 seconds the entire day the laptop was in use. The next day, it failed to boot, with the screen completely off and the caps lock light flashing once every three seconds again. I forced the laptop to turn off, removed the AC adapter, and held down the power button for 30 seconds, and while that appeared to solve the problem (the caps lock no longer blinked while the laptop was in use), the next day, the same issue occurred again, and it was even harder to boot back into Windows. I tried about 8 times until the display and fans were able to come back on; another reset, and the laptop booted successfully again. But I'm concerned that this issue will continue to recur. So far, I've:

• Used the HP PC Hardware Diagnostics Tool to perform a System Fast Test and everything passed except for the short drive self-test, which cancelled while it was 90% completed (the long drive self-test was successful, however).
• Used the check disk, system file checker, and Windows Management Instrumentation (WMI) Command-line (WMIC) to check for file errors; none were detected, and the C: drive's status was listed 'OK'. Also used error checking to see if any errors existed on the drive.
• Used Disk Management to check the health of the disk drive, which were all listed as "healthy".
• Used Windows Memory Diagnostic to determine if there were any issue with the RAM; no problems were detected.

Looking up the blink codes, the error condition appears to be "CPU not functional" I did additional research, but there is not one definitive answer for what is going wrong. It could be a failing motherboard, BIOS (more likely), a RAM issue, or hard drive failure. I don't know what it is, but none of the things I've tried point to any issue. My laptop is nearly 9 years old, a retired product, and no longer has available BIOS or driver updates on the HP website, and my Windows 8.1 operating system has reached its end of support. I don't know what else to do. I'm scared to turn the laptop off and be unable to ever boot back into it. Here's my laptop info:

Some of the BIOS errors as listed in Event Viewer:

And I'm not sure if this is related, but these service errors only began after the laptop started failing to boot: