Sandisk 4GB Cruzer - unknown USB device

chip SanDisk 20-99-00121-1 S647-72006

http://www.imagebam.com/image/2933c7464741001

http://www.imagebam.com/image/37db03464741618

CheckUDisk 5.3
Name: unknow device (USB0.0)
VID&PID: Vid_0000&Pid_0000
Speed: low speed

Can it be repaired?

Is there any program to reset, clear this chip?

Hello, 

first of all i do not know why you opened the drive since it voids the warranty. 

furthermore you can refresh the drives of the drive manually with the system to see if that makes it work again

http://kb.sandisk.com/app/answers/detail/a_id/10/kw/usb%20not%20detected

if that does not help then you can test the flash drive on another pc, if there its also not detected then the drive seems to be defective and needs to be replaced