What happens if you catch the same misdemeanor case while on misdemeanor conditional discharge?

He will get a new driving on suspended license charge AND be charged with something like failure to comply. Or depending on how the original sentencing was worded, he may just be charged with another driving under suspension (making it two counts). Whatever happens the judge is NOT going to be happy, it doesn't matter what the excuse is, the judge was trusting your brother to do the things he ordered him to do. Since he didn't do those things, I imagine the judge will probably give him some days in jail because he can't be trusted to do anything else the judge may ask of him