Quick'n'dirty method (requiring two passes over the file, the first to count occurrences of `$2,$3`, and the second to print whenever the field combination is non-unique):
$ awk -F, 'NR==FNR{a[$2 FS $3]++; next} a[$2 FS $3] > 1' file file
1,1,10,1
2,1,10,3