s7 400

i have face a problem on s7 400 cpu
in running machine a fault is occered on hmi that is"communication fault in plc and pcc"and all lights of cpu is blinking
can any body help me about it

You will need a PC with Step7 to check the contents of the diagnostic buffer.

Refering your other post;
did your S7300 and -400 fail at the same time?

Kalle

It looks like your PLC might be defective. Have a look here:
https://support.automation.siemens....earch&searchinprim=0&nodeid0=10805188&x=0&y=0