N
needhelp
- Jan 1, 1970
- 0
Hitachi 50UX22B projection TV picture shrinks top and bottom.
While it is normal sometimes, often the picture shrinks, with the top and bottom full black, while the middle 2/3 to 1/2 (varies) is nearly normal. Side-to-side is normal. Sometimes the picture returns to normal for a while (seconds to minutes). No pops or snaps.
Sometimes the picture is normal on power-up, sometimes not. Turning off and back on may or may not change it.
Picture resembles " ( ) " turned 90 degrees. It is NOT an hourglass shape.
So far I have:
Sniff test. Nothing found.
Vacuumed out the back.
Inspected for burned swollen, or melted components; none found.
Flexed circuit boards.
Reflowed the solder on about half the connections - some were too tight to try.
I have a repair manual and VOM, but no scope and haven't worked on TVs since the the early 70s.
Ideas?
While it is normal sometimes, often the picture shrinks, with the top and bottom full black, while the middle 2/3 to 1/2 (varies) is nearly normal. Side-to-side is normal. Sometimes the picture returns to normal for a while (seconds to minutes). No pops or snaps.
Sometimes the picture is normal on power-up, sometimes not. Turning off and back on may or may not change it.
Picture resembles " ( ) " turned 90 degrees. It is NOT an hourglass shape.
So far I have:
Sniff test. Nothing found.
Vacuumed out the back.
Inspected for burned swollen, or melted components; none found.
Flexed circuit boards.
Reflowed the solder on about half the connections - some were too tight to try.
I have a repair manual and VOM, but no scope and haven't worked on TVs since the the early 70s.
Ideas?
