Perhaps (and I can't say why) a new "feature" of the BIOS update taxes a marginal power supply. What size is it? Another thing you might try to see if the update is causing this and see if the website for the MB still carries previous BIOS flash files and try to return to a previous version. BTW, most flash utilities allow you to make a backup file of current BIOS before flashing with a new one. It's important to do that. You can damage the system if things go awry. Good luck.
flashed bios, all went well til roboot. pc power down completely. tried to restart which was successful after several attempts to power up. i had to hit power button numerous times (10+). pc came on and ran normally. rebooted- same thing, complete power down and difficulty restarting. once pc is running it- it runs fine. just the problem powering up.
<flashed bios to upgrade vid card on older mobo.>
any ideas what could be causing this?