My Samsung TV set has developed a problem and i need some help fixing it.

When i switch it on some vertical colour bars fill the screen and don't go away until i hit the sides of the set. Its driving me crazy.

What could be the cause/problem and possible solution? Are there any good links to schematic diagrams of TV circuits?

 

My Samsung TV set has developed a problem and i need some help fixing it.

When i switch it on some vertical colour bars fill the screen and don't go away until i hit the sides of the set. Its driving me crazy.

What could be the cause/problem and possible solution? Are there any good links to schematic diagrams of TV circuits?

Its better and safer for you to take the TV to a professional because inside the TV very high voltages are developed which may be lethal.

 

Can't argue with that. The other side of the same coin is I'd rather take it to someone who has already made all their mistakes on someone elses TV, as opposed to mine.

 

If you really want a schematic for your TV, try here:
http://www.samswebsite.com/photofacts.html
They are not free.

But unless you are an experienced technician, I reaffirm the suggestions that have already been made to take it to a TV repairman. CRT-type sets have very high (and lethal) voltage levels on the picture tube for long periods of time even after it's been unplugged from the mains. Even LCD flat screen sets use high voltage (300v-700v) to power the CCFL backlight.

As Bill suggests, it is all too easy to cause far more damage to your set. Giving it a thwack to get rid of the test pattern will reduce the expected life of the set due to the physical stress on the components.

If your TV set is over 6 years old, I strongly suggest you skip the repair and opt for a new replacement set. A 7-year old TV is generally near the end of it's useful life.

 

Just whack it with a baseball bat: http://forum.allaboutcircuits.com/showthread.php?t=12376

 

Have you ever had the back off of a t.v. any t.v.-WAS THE T.V.
DROPPED,OR FALL STAND OR TABLE.We have to determine your
knowledge,once you let us know your experience.Do you have
a soldering gun,have you ever soldered a curcuit board.Anwser's
to these question,s can help us advise you better,who know's
you may have fund's to go out buy a new one.
Read my post about being shocked with electricity I'm lucky
to be alive.Step by step let us know , do you have
electonic tool's.There are member's that could repair a t.v.,
as these guy's say time is money,and they work with low voltage.
There computer knowledge is worth more than any t.v.
If you are going to school to become a engineer,buy a new t.v.
Reply before you do anything,Don't touch the t.v. until you are
qualified.Let us know what equipment and tool,s you have.
Guy's I know you work with high voltage-within 2-feet use that
arc stick.The real bad stuff.

 

Hiya,if someone here could advise a safe way of discharging the juice stored in the set,i would clear the dust/cobwebs,in the back of the tv,with hoover and soft clean dry paintbrush.It stopped my tv from misbehaving[sparks jumping around HT lead on tube].Also i would try another scart lead,or waggle the existing one about a little,to see if the scart lead connection is at fault,thats if a scart is used to connect your tv to a vcr,or sat/cable box
WARNING,the charge stored in the back of a tv can last for days,,,,it will easily kill you.
regards bodger

 

If your TV set is over 6 years old, I strongly suggest you skip the repair and opt for a new replacement set. A 7-year old TV is generally near the end of it's useful life.

Its about 3 yrs old.

 

Thanks to all of you for the safety concerns. However, i'm not so much interested in repairing my CRT TV as in understanding (from an electronics point of view) the reasons it is misbehaving.

All i'm asking for is an electronics explanation.

 

It could be as simple as an accumulation of dust inside the set, coupled with humidity, creating an electrical short somewhere on the main board. If someone in the household smokes, that causes such malfunctions to occur much more quickly, as the sticky tar accumulates rapidly, and attracts dust.

Your set appears to have a bar test pattern generator built in that's used for aligning the CRT at the factory or TV repairman's bench. That might have a pushbutton or "flying lead" jumper to enable the alignment circuit. Or, it could be just bad solder joints.

If Howard Sams publishing (the link I posted above) doesn't list a schematic, it usually means that the manufacturer of the set published a version.

 

Hiya,if someone here could advise a safe way of discharging the juice stored in the set,

Use a 25" shorting probe under the aquadag connection. If you don't know what that means, you probably should not be doing it. Paying for a service tech is a lot less expensive than paying for emergency room copay, or for a funeral.

 

Do you have the equipment to do the repair,have you ever had the back off of a t.v. . Can you reply so we can communicate. This could a learning
experience. LOOSEWIRE

p.s. I need to find out how to edit my post, Look at some of them.

 

Do you have the equipment to do the repair,have you ever had the back off of a t.v. . Can you reply so we can communicate.

No i do not have the repair equipment. Moreso, after the safety warnings from the other posts, i do not think i would want to do any repairs right now. I think i would be OK with some more explanations, like the one from SgtWookie.

 

Probably dry joints.... components..(especially heavier components, or those mounted on heatsinks) that have bad solder connections.

 

You do not need a schematic diagram to fix this problem. I am 99.9% sure is a cold solder joint causing you this problem and is very easy to fix, I have done it many of times.
You will have to open the TV discharge the Flyback transformer, CRT and any large Capacitors or just do not touch any metalics parts.
With the main board backward you can take a visual look to see if you can spot the cold solder joint usually arround the vertical driver IC for this particular problem if you do not see it take the back part of a screw driver (plastic) and hit softly inch by inch until the problem goes away(the TV has to be on for the hitting test) then turn it off and resolder all the parts within that area if you still did not see the cold solder. Sometimes it is extremely hard to see the cold solder and you just solder all the parts around the area where the lose contact was found.