Having run a bunch of diagnostics on my Linux laptop after the wireless died in mid-session, and posted the results to a couple of boards, the consensus is that my Broadcomm wireless chipset is dead. Can I regain wireless functionality by simply buying a USB wireless adapter, or does such an adapter need to talk to a living breathing on-board wireless chipset in order to work itself?
Thank you. After the O.P., I discovered that wireless is not "on board" but is a small (and replaceable) card. After finding one on eBay for 30 bucks, I bought it. It worked immediately out of the box with Ubuntu 9.10, with the peculiar exception that wireless functionality would not come up on a soft boot, only on a power down restart. This was a minor irritation--until yesterday, when wireless stopped working altogether.
I had a slow week at work last week, and thus was able to scr*w around with these issues. But not anymore. I've read some evidence that the onboard graphics borks the wireless, but I'll need to do more research to confirm.
Meantime, the unit makes a fine hardwired quasi-desktop.
Yes, physical switch OK and, at least with the prior card, tried multiple versions of Linux and Win XP. Since my OP, I´ve read an account or two somewhere that the onboard (?) Nvidia graphics (for my HP/Compaq F572US)may indeed kill wireless cards by creating a tendency to overheat, but hell, the first card lasted 3 years and the second 3 days, so I'd very suspicious of that culprit. It could, I suppose, be the wireless switch itself that has gone bad.