Maybe some more information, so we know where to start. :confused3:
What brand might be a good start...
First, does the machine start?
I know zip (nothing) about ZTRs, but I'd check all linkages to make sure the hydro transmission is getting input. That would include the pedals and ranges levers.
Was this sudden? That is, worked great yesterday, today nothing...
Is your hydraulic fluid to the proper level? Filter OK? If a filtering screen, is it clean?
All the above should be fairly easy to check...
EDIT: Since you answered some questions before I posted...a fuse prevented the mower from running? Or, starting? If this machine has an electronic hydro controller (something like Deere's E-Hydro), there may be an electrical problem. Check your troubleshooting guide in your manual and all the fuses.
After that, since it has few hours, suggest you contact your dealer. If you tear into it, you may void any warranty.