Spend some time to find out how to disable the power save option on Bizhub C35, so i just want to share the solution with the Forum 
To prevent the machine from going into a powersave condition prematurely, turn off Sleep Mode with following actions.
1.Press the Utility/Counter key.
2.The Utility Mode screen will appear.
3. Touch Meter Count on meter count display.
4. Press the following keys in this order.
Stop --> 0 --> 0--> Stop --> -->0 -->1
5. Touch Password, and enter the CE password using the display keyboard or the 10-key pad.
Note: The initial setting for CE password is "92729272".
6. Scroll down to Sleep ON/OFF Choice Setting (Allow/Restrict)
7. Select "Allow"
8. Press the CLOSE button to return to the main screen.
9. Go to the following Setting and change Sleep Mode Setting [ON] to [OFF].
Admin Settings --> Machine Settings --> Sleep Mode Setting [ON] / [OFF]
10. Power machine OFF/ON.
If Sleep ON/OFF Choice Setting (Allow/Restrict) is not available, a firmware update is nessesary "
ex. Special Controller firmware A121-30G0-1042-83, Panel firmware A121-20G0-0148-83"
To prevent the machine from going into a powersave condition prematurely, turn off Sleep Mode with following actions.
1.Press the Utility/Counter key.
2.The Utility Mode screen will appear.
3. Touch Meter Count on meter count display.
4. Press the following keys in this order.
Stop --> 0 --> 0--> Stop --> -->0 -->1
5. Touch Password, and enter the CE password using the display keyboard or the 10-key pad.
Note: The initial setting for CE password is "92729272".
6. Scroll down to Sleep ON/OFF Choice Setting (Allow/Restrict)
7. Select "Allow"
8. Press the CLOSE button to return to the main screen.
9. Go to the following Setting and change Sleep Mode Setting [ON] to [OFF].
Admin Settings --> Machine Settings --> Sleep Mode Setting [ON] / [OFF]
10. Power machine OFF/ON.
If Sleep ON/OFF Choice Setting (Allow/Restrict) is not available, a firmware update is nessesary "
ex. Special Controller firmware A121-30G0-1042-83, Panel firmware A121-20G0-0148-83"