s7 300 no comunication

Hello:
I have a problem with an s7 315 plc.and cp 343-1
I lost comunication with the system and I can"t restore it
I changed plc and cp343 also but I can comunicate and configure 'em
but only if I remove the memory card. but when I put the mmc again and try load the program I loose comunication again.
I only have comunication without MMC.
is thera any way to reset the MMC or may be it is damaged?

any help is welcome

thanks

I have once also this kind of problem. Do you have a MPI adapter. Connect with it and clear the cpu. Beware of losing data. Download your hardware and software and maybe it is fixed. Otherwise your MMC has a problem.

Hi
S7xp.com thanks for your reply.
finally the problem was the MMC, I got a newone MMC and when I installed the machine worked imediatly

thanks again

Great, problem solved. Well I searched once a few hours why sometimes my dp comms failed. Finally it was a loose cable in a dp connector.