MPROG shows No device Found

Hi,

In my USB blaster i replaced 93LC46(Micro chip) with other working USB Blaster one.

But know, since EEPROM contains data when i plug in to PC it shows USB-Blaster(with question mark symbol in device manager) So i tried to erase that reloaded with new one, In MPROG when i click scan shows No. of Blank device=0 No. of Programmed device=0.

No device found when i click read button.

But in device manager USB is recognized.

Note:Before this i replaced FT245 also.