SM74 ERROR #91, please help

Hi there!, i am from brazil and this is my first post, our SM74-4H printing press, is showing error code # 91, can someone help on this one ? serial number: 627849, (2 pictures attached).

 

error 91

can you send photos in English pls

 

not sure if this helps but we had a software upgrade to our machine and ever since that we encountered error 91 when we were putting the plates on too quick from unit to unit........turns out that the plate saftey bar was releasing as the press started to move in reverse for the next plate to be removed from the back clamp and this sent the machine into a safety shutdown .....once we clicked on it at the console and removed error we could move again but it just means we have to be a bit more patient and not to eager to change plates at speed.......heidelberg ( germany ) say its part of the software upgrade and wont do nothing about it as its a safety upgrade..

took three weeks for them and several engineers to test over a few visits as they thought it was electrical breakdown in one component and needed to be sure

hope this helps

 

Can you change the press to English and post screen error in English Guess?? looks like it reads Detection Of Movement ?? who knows
what is the press software. translate it in English please .. and will try and help

91 means many things. Provide more info please.

When does it occur ?
How often does it occur ?
Has anyone had a look at it. Service Tech ?
How long have you had the fault ?
What do you do to clear it i.e. reboot the press or clear it from the screen. ?