Replacing The Power Supply Pcb And Monitoring Pcb Of The; Fan Subassembly - Siemens SIMATIC S7-400 Hardware And Installation Manual

Maintenance
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).
Quick-release
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
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Fan 1 Fan 2
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Power supply Monitoring
PCB PCB
S7-400 and M7-400 Programmable Controllers, Installation Manual
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Fan 3
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Quick-release
Reset button
lock
C79000-G7076-C424-01