I have a Dell Inspiron 530 desktop, which runs XP pro, and perhaps most unique to this system, was config'd to dual-boot the Windows 7 release candidate a couple years ago.
Recently this system developed a most bizarre startup behavior.
When powered on from a cold start, the power button light goes from dark, briefly to amber, and then blue, and the fans spin up at max speed as usual. Normally after a second or two, there is a single beep indicated successful POST, the fan speed dies down, the BIOS splash screen comes up on the monitor, and after a moment goes on to the dual-boot menu from there.
That's not how it works anymore.
With just one push of the power button, from a cold start, the fans spin up, the button goes blue, but after about five seconds, with no video output, the system shuts down. But then after 5 seconds it tries again, and fails again. And after a further five seconds, it tries a third time, and apparently three times is a charm, b/c the third time, the single POST success beep happens, the BIOS splash comes up, etc etc.
The bizarre thing is that it's always three times. Not two (as heathens do), nor four, and five is right out. Seriously, though, if this were a hardware failure issue, I'd expect it not to be so deterministically repeatably three. If it was just the PS being overloaded, it might shut down, but why would it attempt to restart? If it was a stuck power button, why wouldn't it just cycle indefinitely?
This isn't a hard-fail, but it definitely isn't normal, and I'd like to fix it.
There's only one other thing I think might be related. The system had just acquired windows updates and wanted a reboot. (running XP; I never start the 7RC image anymore) Normally I dismiss those nag-dialogs and shutdown or restart manually. This time I told the nag-dialog ok, restart now. Could be a coincidence, but I'm not so sure.