omh@cs.brown.edu (Owen M. Hartnett) (06/14/90)
Here's a fix for those wavy lines in your Applecolor monitor: My 13" Applecolor started displaying wavy lines scattering through the display. Nudging the monitor or turning off, then on, would reset the monitor to stability, for awhile. Eventually, the lines would return, however. Larry Pina suggested cracked solder joints and sure enough, several pins on the flyback transformer showed the telltale "nipple" effect. Resoldering returned the display to normal. Here's how to do it: *Warning* *Warning* If you thought there was a lot of high voltage in your black & white Mac the color monitor is much worse! This procedure involves discharging the high voltage anode on the color picture tube. If you don't know how to do this, don't attempt any of this. As a matter of fact, if your Mac is under warranty or AppleCare, or if you have no technical pretentions, let an authorized dealer do it. As a matter of fact, I am not recommending that any individual do anything with his Mac, but if he wanted to do so I will recant the steps I took in my repair. Place the monitor face down on something soft. Remove the screws on the case of the monitor with a phillips head screwdriver. Using a "case- popping tool" carefully pry around the edge where the back cover meets the front. (for you long-time Mac poppers: the monitor case will pop much easier than the Mac Plus case) You may not need a case popper, the case is not particularly fast. Discharge the high voltage picture tube. If you don't know how to do this, close up the monitor and take it to a dealer, don't bother doing this yourself. Remove the wire cage shield which encloses the bulk of the electronics. There are 5 or 6 screws. Now position the monitor, still face down, so that the right side of the monitor (when viewed from the front) is nearest to you. You should be seeing a printed circuit board. Near the middle of the board on the right side (equivalent to the bottom of the monitor when in its usual position), you should see a semi-circular arc of solder joints. This is the flyback connection. Examine the solder joints for cracks. These are noted by rings around the pins that are soldered to the board. A good solder joint will be clear and shiny and not have any markings in it (like mercury) - a bad joint will show tiny "nipples" in the solder. To fix, reheat the joint with a soldering iron, add a trifle more solder, and make sure the joints are good. Finding these cracks will probably fix your problem, and it's cheap to fix. Now reassemble the monitor and enjoy flicker free viewing again. -Owen Owen Hartnett omh@cs.brown.edu.CSNET Brown University Computer Science omh@cs.brown.edu uunet!brunix!omh "Don't wait up for me tonight because I won't be home for a month."