The sound is fading from my samsung projection tv

SOURCE: I have a Samsung rear projection 42in. tv, the

This is evidently a CRT-type projector TV (the owner's manual provides a convergence procedure and warns against operating the set near magnetic field sources - these distort the picture in CRT displays - but has no mention of changing lamps as used in other types). The first thing to check is whether the CRT coolant fluid has discolored with age or algae contamination. This can be determined by visual inspection of the top of each picture tube.

Inspection procedure
CAUTION: there are potentially lethal voltages present inside the set, even it when it is turned off. Some components, including the picture tubes, can hold a charge for a time after the set is unplugged, and some parts can be ruined by static discharge from your fingers even if the shock is too small for you to feel it. Bottom line: don't touch the circuitry unless you know what you are doing.

First, unplug the set, and remove the back. Look for the three picture tubes (sometimes called "jugs" or "cannons") pointing up towards the curved and faceted mirror in the upper section of the set. These are usually mounted on a horizontal black-painted board or panel above the electronics. At the top of each tube is a lens about 7" across. Through the lens you will see a red, green or blue colored face. Using a flashlight, look down into each picture tube. If you see a muddy yellow cast to the color, that confirms the problem. If you have trouble identifying the picture tubes, make sure all hands are outside the set, plug it in and turn it on. Look for the red, green and blue light sources, but be careful not to touch anything or put anything metallic inside the set while it is plugged in. (Some Samsung models allow you to remove the entire projector screen assembly - everything above the control panel - as one piece. These are relatively simple to work on for this problem.)

If you need to change the CRT coolant, check the link here. Plan on it as a full weekend (or two) project if you want to do it yourself. An experienced rear projection TV tech could do it more quickly since there would not be so much time spent looking for connectors, attachment points, etc.

Posted on Oct 27, 2010