Hey,
I'm trying to read from and flash to a W25X40ALSNIG [0] that's still mounted to its hard drive PCB. Following the table from the raspberry pi wiki page [1], and assuming the raspberry pi pin numbers it mentions are physical pin numbers (and not the pi's strange GPIO numbering scheme) I connected the legs of the flash chip to the raspberry pi's GPIO pins. However, when the two are attached, the pi won't boot (it'll show the three raspberries in the corner, then it shuts off). I've isolated this to the VCC (connected to header 17, 3v3) and GND (connected to header 25, GND) , where having all of the legs of the flash chip detached from the pi except for those two will reproduce my problem (I hope testing that didn't actually kill the chip). What am I missing?