After power failure, the S7-410-5H RACK 1 shows the EXT F and BUS F leds on, attached are the Diagnostic Buffer for both Racks. The IM153-2 redundant modules shows BUSF1 and BUF2 leds on. I see in several IM153-2 both channels with BUSF1 and BUSF2 leds on too. The S7-410 5H has EXT F fault it means the failure is in the S7-300 hardware, can you support me in order to find the problem in the HW structure. 

Hi Edegel 1

If you are using a profiBus to communicate between the processor and the IM cards, make sure the connection and settings on the profibus connector are correct.
Set the deep switch on IM cards and check with the values ​​recorded in the software.
The hardware version must be exactly the same as the values ​​recorded in the software.
Finally, save the program and then download