kraut@ut-ngp.UUCP (Werner Uhrig) (08/25/87)
In article <6014@ut-ngp.UUCP>, wmartin@ut-ngp.UUCP (Wiley Sanders) writes: > >Normal? No way. The symptoms you describe are generally associated with ..... > Not normal but not unusual. Judging from the traffic on this newsgroup, > a _lot_ of Macs have failed this way. Also, I don't think there is any > adjustment that can be made that will get rid of the twitching screen. > You just have to wait until it fails completely or else is so bad you > can't stand it any more, then gat another board. I know very often it turns out that the problem can be fixed with little work (local repairshops still have been charging $150 for it, without mercy). WARNING: do not try to repair your Mac internals if you don't know how to prevent damaging it or yourself !!! there is a 4-wire connector with a little latch which connects to the analog board in the top left corner (looking at the board from the inside of the Mac. these 4-wires connect to the CRT-yoke controlling horizontal and vertical deflection. The analog board tends to get so HOT at this connector that the solder tends to heat up to such a degree that cold solder-connections can develop. The fix is to reheat and recreate a GOOD connection and to get a fan to prevent such problems in the future. I have fixed several boards this way already ...... -- kraut@ngp.utexas.edu