My arduino flasher, although I appreciate it, is running into the same issue as the teensy flasher. It says there is no chip when one is there.

I've reseated connections that look loose. I've replugged the usb cable. I've reseated the flash chip and verified it's not backward. I've tried a 10uF capacitor instead of a 100nF. I've put tape under the arduino in case it's shorting on something below it. Same behavior.

I've also labeled the lines! And plugged in my oscilloscope and wired its probe ground to the board ground.

Plan is to plot the clk line just to get comfortably with measuring a logic line.