Tip & How-To about Televison & Video
Your projection TV works but the only visible part is a thin horizontal line across the screen. What happened and how do you fix it?
Your problem is that you have no vertical drive, only a small horizontal line across the screen. In older projection TVs this is usually caused by broken solder joints in the area of the vertical IC and over the entire board. It could also be caused by a bad vertical IC. Let's approch this problem one step at a time.
Disconnect the power. Remove the back cover. Remove the board with the vertical IC which is usually the board with the high voltage transformer on it and it is usually on the right side of most TVs. You can also identify the proper board by looking for and following the wires from the yoke which is on the CRT neck. There should be a yellow, brown, green and red. The yellow and brown are the vertical wires.
Before removing any wires mark them with a sharpie or a label maker. Just make sure that you will be able to reassemble the unit without mixing up any wires.
Usually the board in question is on the right. It will be the one with the flyback on it. The flyback looks like a small cylinder with about 4 large wires coming off of it. They will be red rubber and flexible. One goes to each CRT.
You will need to remove the entire assembly to get to the underside of the boards to solder the unit or replace the vertical IC. Sometimes removing the restraints will allow enough room to flip the board over and do the work without removing all the connectors and removing the board.
Once the underside of the board is exposed, solder all connections on the boards. Be careful not to bridge any connections. Test the unit for proper operation.
If the unit still does not work properly replace the vertical IC. It usually begins with LA followed by 4 digits. It will be in the vicinity of the flyback probably towards the front of the board. The Ic will be attached to a large aluminim heat sink. Make sure that you do not bridge any of the circuits when soldering. Replace the IC, reassemble and test.
If things went well the unit should work ok.
Thanks for using FixYa and for the great rating. Please consider a testimonial. Thank you.
Posted by Kim... on
Mar 17, 2015 | Panasonic TC-P46C2 - 46 Inch 720P Plasma...
Apr 30, 2011 | Samsung HL-R6168W 61" HDTV
Nov 21, 2008 | Panasonic PT-47X54 47" Rear Projection...
Apr 01, 2008 | Sanyo DS31590 31" TV
Feb 17, 2008 | Televison & Video
648 people viewed this tip
Usually answered in minutes!