I have a late 90's model SD Hitachi 52" Rear Projection TV (don't have access to the model number right this second) and I've recently (in the last month) started having a disturbing vertical compression problem:
When I turn on the TV, the entire picture is compressed vertically into the middle third of the screen. After a few minutes, the compression clicks over to about 3-4" of black at the top and bottom (the picture is slightly more compressed on the sides than in the middle). It will occasionally click back over to the original size, however these brief moments of respite are growing further and further apart.
I am reasonably electronic-savvy, and would like to repair this problem myself, but I'm having problems finding information about the parts, tools, and expertise needed (if any). I'd greatly appreciate any advice.
Check and re-solder the entire main board. Use a magnifying glass to get a good look at the joints. They are going to be hair line cracks, so you need to get a GOOD look.