I had to reinstall the 727-100 base pack and the 727-200 expansion model. The installation never ask me the order number like it is suppose to do so from what I read in the user manual. The installation progressed without any errors. After the reinstallation, none of the overhead panel buttons works and I'm not able to turn on the battery from the engineer upper panel. The battery cap doesn't lift up. I guess the problem must come from the unsual reinstallation behaviour. I don't know what else to do to reinstall the product correctly. Can someone tell what I'm doing wrong in the reinstallation process. Thank you for your help.