This problem is not always associated with a heat sink problem. A PDS card or terminator card must be installed in the PDS slot at all times. If this convention is not followed, various video errors can occur.
Please also note that if the PDS card or term card is not installed the customer may experience other issues. (Such as crashing, unable to boot, or freezing). If a customer has a NUBUS based machine and it is giving odd errors please check to make sure that there is a card in the PDS slot.
Machines Affected: Power 100 and Power 120