I have a problem with my Macintosh SE / 30. More precisely, I only see the underside on the screen, ie from the center to the bottom. The other half, the one from the center up, appears completely black. I have tried searching all over the web but it seems this problem is not common.
Since it doesn’t look like the display is “squished” (with the entire display in that area) I suspect one of the two 41264-15 used for video RAM (UC6 or UC7) is at issue. It could just be a bad solder joint causing the IC to be unpowered, or it could be the IC has gone bad and needs replacement. It could also be one of the address lines or one of the counters that drives it.