I recently downloaded the last firmware version to my CPU , after that plc stopped responding in such a strange manner, when I download a program and tries it nothing happens ( I tried different simple i/o programs) I have been trying to solve this for a long time , I tried the following:

-checking connections

-clearing memory (manually and using "Clear&Reset" button in SIMATIC Manager)

I have no idea where the fault might be , also I don't think there is a problem in communication as I can give stop, worm restart force and other orders to CPU and the led lights, when I monitor the program when I force an input it shows me as if it's related output is active but when I look at the PLC

it led don't light up and there is no output voltage.

please reply as soon as possible,

thank you