It looks like you've applied in a closely related anzsco code but this seems more relevant
Business Machine Mechanic –ANZSCO 342311. Installs, maintains and repairs electronic business equipment such as multi-function devices, photocopiers, scanners, fax machines and cash registers.
I'm guessing though as 342311 isn't on the 189 list and is only available on the 190 for one state you've tried to massage his skills into the 342313 job code which is much more in demand.