go to the digi cabbi web site and look for the contact. call in the people and make an appointment for servicing. if the PCB spoil maybe replace one which cost ard 30-40 bucks, if the heat sink unit spoil it will be more difficult to replace, got to check it out the price with them too.
i did mine change on the PCB after 2yrs+ usage at FOC. they know the age of the cabbi without the warranty card (5 yrs warranty stated too).