Yesterday, I had to move two of my machines. When I set them up again, neither would work. Both had previously run 24/7 crunching BOINC projects. I can't remember when they were last powered down, but it was probably not this year. Both are quad core Intel machines.
First machine, when powered on, seems to be trying, the fans start etc. but after a "short while" it stops, then after another short while, seems to try again, and again, and again. The short while in quotes is not a fixed time period, it varies from less than a second, to as long as perhaps 7-8 seconds. It has an SSD which has been there about a year. It has Ubuntu on it.
The second machine powers up, fans running, but does nothing else. This machine is a little older than the other, with a mechanical hard disk, and Windows XP.
Neither machine is displaying any kind of boot messages, or BIOS type messages.
So, what is going on here?