I got a new comp. with BenQ DW1620 , or at least I taught so, it turned out it was a clone (and it looks like I/O magic drive). In device manager it showed as ATAPI DVD DD 2x16x4x16. I flashed f/w using WinDWFlash and B7S9.svc. (finally, after a few others) Now it shows as BENQ DVD DD DW1620. But when I try to watch a dvd the comp crashes when it comes to dvd menu. Event viewer says: Event viewer says: The device, \Device\CdRom0, has a bad block.
Hi - so long as the device retains its ID-string [whatever that may be] you can probably re-flash it.
Safest IMHO is to do it in DOS with a clean driverless DRDOS floopy from (say) www.bootdisk.com & the Dangerous Bros DOS flash-tool (v 1.1 - on their page) & your chosen *.cvt
 assume you’ve read the labels on the drive to make sure it is a BenQ 16xx . . . . .
Some of the I/O magic are BTC, not benq. you may want to check yours.