Siemens S7-400 installation manual Exchanging the Mother Board

Maintenance

7.10Replacing 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
Quick-release	Power supply	Monitoring	Quick-release	Reset button
lock	PCB	PCB	lock

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).

7-18	Automation System S7-400	Hardware and Installation
		A5E00850741-01