A whole row or column out would suggest a broken join at the edge of the glass on the DMD ( where the flat wire pieces come out of the glass ) .

A partial column could not be this .. 

Perhaps it could be just a bad join / connection from the ribbon cables running to the DMD .

Have you tried removing / cleaning / re-fitting all of the connectors associated with the DMD ?  Do both ends .. ie. the end that connects to the DMD as well as the end that connects to the board in the backbox .