Did you change the cell type in the installer menu? That should be the only thing that needs reset I believe. 28V and 5.0 + Amps would indicate that it is working as that is what i had on mine before the end of this last season as well. I am using an SC-48 but getting only 28V, 1.5 Amps currently. Have checked everything else and all things seem to be pointing to the cell?