Helps if you have external 3.3v power, I have a BlackFlash USB which comes with a BlackCat USB and USB to TTL together, I grab the 3.3v from the latter and apply this to the VCC SPI pin, the rest SI to SO, SO to SI, SCLK to SCLK, CS to CS and GND to GND like the diagram shows (make sure you flash bcusb with spi avr firmware beforehand)
Then you power up bcusb (leave the dta powerd off) and bcusb should power and detect the chip
BTW I think the spi chip is a Winbond if I am not mistaken, its usually the one with paint on it
Edit: just remembered, if you don't have a usb to ttl to grab 3.3 or 5v from, you can always use the voltage selector pins from the bcusb like I described how here, or if you have the new fcusb pcb 2.1 you can grab the power from the underside
Then you power up bcusb (leave the dta powerd off) and bcusb should power and detect the chip
BTW I think the spi chip is a Winbond if I am not mistaken, its usually the one with paint on it
Edit: just remembered, if you don't have a usb to ttl to grab 3.3 or 5v from, you can always use the voltage selector pins from the bcusb like I described how here, or if you have the new fcusb pcb 2.1 you can grab the power from the underside