Had a power outage, not a surge, now reads call for service.

"HDD mount" means it has an internal hard drive (HDD, or hard disk drive), and the copier has failed to "mount" (place in operation) that disk drive. That error means that the internal hard drive has failed and needs to be replaced. It will very likely need to be a special proprietary hard drive, preloaded with some sort of operating system for the copier, and you'll need to get it from a dealer.

to start your computer again

try replacing the ram

press 1+3 +star mc on

Developer must be replaced by a technician. Old developer has to removed and new installed. Then there are software adjustments and counters to be reset as well.

clear very well the paper path especially if there is bridge who trasfer the paper to the finisher and check the sensor inside it or check if there is any load at the main motor

Your copier is likely trying to print to a different thickness of paper (ie thick 1/thick 2) then you have in whatever tray it is trying to print from. You will either have to change what is in that drawer via user functions or delete the job and try it again with a different paper type.

It depends what the copier is doing, is it giving error codes
one of the main faults on the copier is it dumps colour toner and that causes problems
need more info

You need to post the error code (top right hand corner of the screen

what model if is Toshiba e-35 or e-350 all this machine is B & W you only can print in colour with e-3511 or 351C or 2500/3500 machine