So I tried to start my Debian box earlier today, and it wouldn't boot up at all. Most of the hardware seems to be working fine, but the monitor won't turn on. I'm not seeing the boot screen, it's just black. Also, the caps lock and num lock keys are blinking.
A little background on this computer. It's an HP Pavilion model, and I've installed Debian GNU Linux on a hard drive partition. I had it off and unplugged for possibly a year or more, then I turned it on for a few minutes, then turned it off again. Now when I try to turn it on it won't start. It was working perfectly fine before, no signs of imminent component failure whatsoever. The only thing that happened between then and now is it was off and unplugged for a while. My best guess, based on my limited understanding of computer hardware, is that the CMOS battery died due to not charging for two long periods of time. This would mean that the BIOS settings are lost and I will have to take my computer in and have someone manually reset the CMOS. I think that if the BIOS was working properly, and the problem was, say, a hard drive failure, I'd get some sort of message like "Operating system not detected." If I get no message whatsoever, common sense dictates that it's probably a firmware issue.
So my question is, based on what I have told you, have I made an accurate assessment of what is probably the issue? If not, what other problems could have occurred? I don't have a lot of money and won't be able to get it diagnosed by a professional for a long time, so I just want to get some idea of what's going on.