@mathlover Try hitting F2 or F9 at power-up. It should enter into Bios and allow you to list the hardware. Simply exit then, without changes. If that happens, most likely it’s an Ubuntu update that broke the bootloader. Otherwise it may be a hardware fault. If at boot it beeps a number of times, then it’s a hardware fault. You could google “hp N beeps at startup”, you can find what it means.
@luci Hitting F2 does nothing. Neither does hitting F9. No beeps occur
@mathlover F3? F10? Sorry, it’s usually one of these four for most laptops. You could look at HP support site, trying to find the exact info for your hardware, but that takes more time…
@luci I think you are very likely right.
Good news is that the hard drive was not the source of failure, so once I get the appropriate adapter cable I will be able to transfer all the data I need from it (I frequently back up my data anyway as is, so there's not a lot I need to account for)
@mathlover I have seen laptops used for 8 years. 12 is quite a lot, especially if it was powered on most of the time. I understand the attachment, but please know that the machine is already a champion who may have no choice but retire.