S7-200 (216-2AD23-0XB0) - port 1.4 only blinks

[arhi]

I googled, read the datasheet and finally gave up. I have a following problem on S7-200, cpu 226

I1.4, when I bring 24V to it the led on it only blinks (does not stay on) and in live view on microwin I do not see anything happening on that port. (the I1.1 for e.g. works ok, led's on while 24V is there, live view show the change..)

any ideas? do we have a dead port, misconfiguration of a port or something else?

thanks

 

[arhi]

Just to be clear on the "blinks", it does not gon on/off/on/off/on/off ... it only goes on for few ms and then goes off. Only if you remove the 24V and apply it again, it goes on again for few ms and then stays off.