Quite a strange problem - not one that I've seen before.
The notebook shows the Fujitsu Siemens power-on screen, but doesn't proceed past it, just sits there on the splash screen indefinitely. No beeps, doesn't go black, doesn't proceed to boot. If I press F2 as soon as the splash screen comes on, it disappears and I can see the POST messages, including the one announcing the intent to go to BIOS setup, and if I then press F12, it also shows a message about going to the boot menu. But as soon as all the tests are finished (and they all pass) the computer hangs.
I'm not sure whether it's relevant but at the time the problem started I was trying to do a clean Windows 7 install over XP (and kinda failing - I've since discovered that this is a perilous procedure on these laptops), and I'm pretty sure the MBR is broken right now. Of course, this doesn't seem to matter, since I had restarted a couple dozen times without error before this problem appeared, and in any case, it doesn't seem to proceed to the boot stage anymore.
Any suggestions?
Cheers,
Mark.