Problems encountered in the raspberry pi 3 Vcc Glitching?

Hi:
I have a problems in the raspberry pi Glitching experiment,my hardware model raspberry pi 3 model b V1.2, The IC is BCM2837,Chipwhisperer is ChipWhisperer-Lite(CW1173),I follow the instructions from wiki,then solder a wire onto the VCC side of a decoupling capacitor, such as C67,But it doesn’t work,The CPU frequency is 1.2GHZ,I’ve tried a lot of frequency and repeat settings,What may be the reason?Thank you very much!!!