Macintosh SE/30: Screen Bowing Problems



My Macintosh SE/30's screen bows on the sides when there is a black
rectangle displaying. This happens, for example, in Excel when I select
three or more cells and highlight a whole row across the entire screen.
When I deselect, the bowing stops.

I've replaced the analog board, the power supply, the video board, the CRT,
and disconnected the hard drive--all to no avail. Is it possible that the
system board is receiving interference from something else in the system?

The problem you're describing is usually caused by one of three things:
* defective analog board,
* defective video board, or
* internal contrast setting set too high.

Even though you've already replaced these components, we suggest you
recheck them (particularly the video board) for possible defects.

Though the logic board is a possible cause for this type of problem (since
it maintains the video image in VRAM) it is unlikely to be causing the
problem. If the first set doesn't solve the problem, however, then go
ahead and replace the logic board.


Published Date: Feb 18, 2012