EEG source localization without digitized electrodes and subject MRI

https://neuroimage.usc.edu/forums/t/easycap-64-channel-location-setup/1027/2
Hi Francois,
I've been puzzled by a problem for a long time. I want to compute sources ,but i don't have the channel location. Now, i use default EEG cap, am i right? If it's wrong, what should i do?
Thanks for your help
luzhou