This article is from the Apple II Csa2 FAQ, by Jeff Hurlburt with numerous contributions by others.
Monitor RepairMini-Manual (Q&A 001-014) 4/98 version This mini-manual describes Repairs & Adjustments which usually involve removing the case. Before removing the case, check to see that the your problems are not due to a poorly connected monitor cable or misadjusted monitor controls. By: Rubywand Maybe. First, check your cable connections to make sure they are solid. Also, try diddling the side and back controls. Sometimes, these become dirty or develop bad spots. If diddling a control seems to cure or nearly cure an unstable, jumping, etc. display, you can be fairly sure that a squirt of Control Cleaner will help. The cleaner needs to reach the control's resistance element-- the place where the wiper touches the carbon track in a potentiometer-- and you should turn the control back and forth after squirting the cleaner. Probably, you will need to remove the case to get a good shot at the dirty control. = = = = = = = = = = = = = =