Ideapad Y510 BIOS Flash Process
1. Copy BIOS file (06CN33WW.ROM) to USB disk or your HDD.
2. Press F2 key to enter SETUP mode in POST or Press F4 key to Flash mode in POST;
3. Advanced ->Start Easy Flash 
    Start Easy Flash: Easy flash interface for upgrade BIOS 
4.  Find BIOS file on your HDD or USB disk, then run it .it can Flash BIOS to new ver.
     Tips: please hold AC adapter and Battery on your laptop at the same time.
    
Note if the USB drive is not detected in the Flash Utility program, it is necessary to configure the USB device as the first hard disk drive, as follows:
Boot->Hard Disk Drive->Change USB device to 1st drive.

For more details, please visit: http://consumersupport.lenovo.com/en/HintsandTips/hints_show_1231913189017.html