Colour problems

Thought that getting into the service menu would give me more options to repair the machine . But unfortunatley not ! having a reoccuring problem were all the colour units fade and almost no colour is printed but black remains unaffected , but problem seems to disappear after machine has calibrated itself genarally after restarting wich is time consuming !! wondered if anyone had any ideas as have tried replacing almost everything on the machine !! some one mentioned spring kits but this has resolved nothing !!

any idea would be greatly appreciated

many thanks