not printing the last 3 pages

the machine is running fine until you stop the machine then the last three pages does not print. only the black prints but not the colours

 

What press is it and how old? Some of the older Komori's used a sequencer to control each units forms and impression, on and off. Are you running black in the first unit and when it comes off impression the next three units also come off impression? We need more information to point you in the right direction.

 

it is a komori l-425 bp Yes we are running black firstand yes when it comes off impression the next three units comes off at the same time

 

The older L-425Bs used limit switches to turn on and off impression. A problem on the 4th unit could cause units 2,3 to trip off when the 1st unit went off impression. Later L-425Bs used a signal timing device to turn on and off each unit based upon the action of the first unit (which was controlled by the Eyekom). Most of these have been replaced by a brick PLC, available from Komori. So if you have an older model I would start with the limit switches and if you have a later model I would check if you still have a signal timing device. It is usually located in the main electrical cabinet and have black "mini rot" relays on it.