My picture tube displays all black except one thin horizontal line in the middle. There are no horizontal or vertical adjusts that I can fine. Is the picture tube burned out with just this one line?
A thin horizontal line across the screen denote that the vertical swep or output has damaged, or there are some loose solder points to vertical output section. Loose solder problems are very common to the vertical output sections of most of the picture tube based TVs. Just open your Tv, and pull out the main baord out of it, which has the vertical output section circuit. You must have some knoldge in electronics to proceed. Locate the vertical output section. usually, this section will be composed of an IC, which will be screwed on to a metal heatslink, to radiate heat out of it when it works. Check whether there is any loose solder terminals at this section, especially look for it at the solder terminals of IC and other components around it.
It is very difficult to detect the loose solder points, as some of them may be so microscopic to detect. Just do, what we do at service table, with this type of fault comes to us. Just resolder most of the suspected solder terminals by applying a little more solder without making any sokder bridge short between adjecent solder terminals.
If this does not help you, check the input voltage to the vertical IC. If found OK, replace the vertical output IC. If there is no voltage to this IC, check the track that brings voltage to that IC. Usually, this voltage will come from one amoung the terminals of LOT [Line Output Transformer]. Check the track, rectifier diode, limiting resistor etc. This is really a skilled work, and you should have all tools for an electronic work, and a skill to detect the faulty component. OK
Sep 16, 2011 |
Durabrand DWT1905 TV