GSA-4120B crashed after firmware upgrade

I hope some expert in this forum can give me some insight.
I tried to flash my GSA-4120B from A102 to A115, it turned out
“fail to update” and its firmware dropped to COR1. Since then,
My drive even can’t eject disk by pressing the button. I tried
different firmwares, but all have the same problem.

I also tried to flash several times, but after 1 to 2 times, the dvd
drive will be “kick out” from the system, I need to cold boot the

OS: Windows 2000 server
Chipset: VIA
IDE: 2nd master

Please help…