unable to do z print in towa ex300

hi

i have towa ex300.from last night i have problem that goes like this:

in r mode every thing i pressed i got the massage no-cl and i couldnt do anything.
i tried something i read in the forum, and insert 1 to the clerk botton (st/#).
since that point i can work on the register but when i goes to z mode, i cant print nothing there.
beside that i have blinking light above cl5 on the small screen (where i see the amount of the transaction).

would realy like to get some help here

thanks

yaron