Funny you say that. Mine died this Sunday after the same firmware update (3.0). I have the very first model of PS3 that came out (60GB with 4USB port and backward compatibility with PS2 games). My boy plays it most of the time. He updated the firmware Sunday then rebooted and played for 1h - no problems. Then the following day, turned it on again, played 5min and the bloody thing turned off. Wouldn't boot. Green light, beep, flashing yellow light then blink red and red -> power off.
. I tried to clone the drive but it's a *nix partition so I got stuck. SONY won't even look at it if it has been customised or if you've changed the original drive. It's also company policy to format the HD when they service them. Something to do with privacy laws.
Anyway, it's with SONY now. $250.00 later. Got to wait 3 weeks to get it back.
I've had the console for over 3 years now, updated the firmware many times. It's in top nick, never had the problem. First time.
IMHO As far as fixing goes, even if it's out of warranty pay the $250.00 and get SONY to do it. If you get it done somewhere else and it fails (which it will coz only SONY provides reliable parts - they've lobbied the market for good parts) then you're stuffed for good. I have a mate who worked for SONY for years and he's heard them all.