Siemens Automation System S7-400 - Manual (Page 166)

Maintenance
7-18
Automation System S7-400 Hardware and Installation
A5E00850741-01
7.10 Replacing the Power Supply PCB and Monitoring PCB
of the Fan Subassembly
Exchanging the Mother Board
1. Disconnect the power cable of the fan subassembly from the supply.
2. Use a screwdriver to make a quarter turn counter-clockwise and open the two
quick-release locks on the front of the fan subassembly.
3. Remove the base of the fan subassembly (see Section 7.9).
Shown in the following figure is a front view of the fan subassembly. You can also
see the locations of the printed-circuit boards (PCBs).
Fan 1 Fan 2 Fan 3
Power supply
PCB
Monitoring
PCB
Quick-release
lock
Quick-release
lock Reset button
4. Pull the faulty PCB forward and out of the fan subassembly.
5. Slide the new PCB in until it engages.
6. Slide the base in again and press it up.
7. Use a screwdriver to make a quarter turn clockwise and close the two
quick-release locks.
8. Connect the power cable of the fan subassembly to the supply.
9. Use a pointed object to press the RESET button. The fans will start running.
!
Caution
Electronic components can be damaged.
If you do not observe the ESD guidelines when handling printed-circuit boards with
electronic components, the components can be damaged by a static discharge.
Observe the ESD guidelines (see Appendix).