980g no functions, no hydraulics, no drive

hey somehow i got myself into working on this cat 980g at work and not having any information on this is not helping me....i have no hydraulics, no steering, no loader bucket etc etc. and also the machine will not move...what would cause them both to quit at the same time? what should be first diagnosis step be? being a case technician the systems seem pretty different

980g no functions, no hydraulics, no drive