Help! Is My TV Dead?

[Techforce]

Can you post a model number?

[Sam Goldwasser]

Probably either bad solder connections or a component that is heating up and failing.

In either case, it will need service. If the TV works well otherwise, it may be worth it.

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[Doug Miller]

The most obvious idea is that you have learned why it was in the trash pile. :-)

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[BinaryBillTheSailor]

Observe all proper safety precautions, and resolder the connections to the flyback to see if that cures it.

BB

[Rick Brandt]

The flyback is the transformer looking thing with a large wire coming out the top and attaching to the bell of the picture tube. It's also one of the things that will ruin your day if you touch the wrong spot.

Also keep in mind that a TV also has places that can ruin your day if you touch them even with the power off. In addition to some largish capacitors, the tube will store many tens of thousands of volts of static virtually indefinitely unless the technician specifically dissipates it.

The old rule was "one hand in a pocket at all times".

[Rick Brandt]

Well there could be several, but the suction cup looking thing is definitely one of them. Just be careful in getting the board set up where you have access to the solder joints and then avoid touching any circuit that you don't have to.

The flyback is a notorious area for developing bad solder joints. Often you can even see discoloration where the circuit was arcing so see if you can find any of those. It is also not unusual for these failures to be internal to the flyback so many times you can resolder the whole board and it doesn't help.

[Fred Mann]

I have a Samsung TV manufactured in 1998. I picked it up from a trash pile on bulky-item pickup day!! To my surprise, it worked fine. But occasionally, the picture would "compress" or shrink in an oscillating fashion. It would "shrink" in the way that the image "shrinks" when you turn off a TV (right before the screen goes black). It would oscillate, and sometimes turn itself off. (sound was fine) Gradually, this started to happen more often, until it began to turn itself off after only a couple of minutes. Now, when I hit the power button, the TV does not come on at all, but there is a "click" sound, followed immediatley by another "click" sound as the TV shuts itself back off. Any ideas? Thanks!!! Fred

[Techforce]

Theres a history of Vertical problems in this set. Sometimes it winds up being the EEPROM, other times components need to be changed. I gather when you say 'compressed' you mean vertical collapse?

[David Martel]

Fred,

A TV will have only one flyback transformer. As everyone else said BE CAREFUL

Dave M.

[Fred Mann]

It's TXG2547

[James Sweet]

occasionally,

When you started out it was a simple cold solder joint, probably would have taken 20 minutes to repair and well within the reach of a novice. By continuing to use it you probably blew out the horizontal output transistor or something in the power supply, it's still repairable but it'll take a lot more work now.

[James Sweet]

First bit of advice, read the sci.electronics.repair FAQ, if you can solder then you're on your way but *read* the safety stuff and make sure you understand it first. If you search for flyback transformer online you'll find pictures of them, I strongly suspect something else has popped though.

[Fred Mann]

occasionally,

I don't know how to identify the flyback. I have soldered and desoldered things, but I don't know TVs too well. Do you have a link to a diagram/picture, or can you explain how to locate the flyback?

[Fred Mann]

The part with the suction-cup-looking thing? Which spot is the wrong spot? (tantalizing) If I can do this without dying, I'm game.

indefinitely

[Fred Mann]

THANKS!! Where would the other flyback be?

[Jamie]

ok, i have my other hand in me pocket!, what do i do with me gutt that is sitting on the edge of the bench ? :)

[Jerry G.]

This sounds like some components in the vertical deflection area have become intermittent, or thermo sensitive from age. The set is fixable by someone who is properly trained, has the service manual, and the proper setup to service it.

In the set, there are also some software criteria's with the EPROM, and the internal software. There are times, when this is a problem as well. In your case, it may just be some parts that have to be determined, and changed. It would be a wild guess to make an exact recommendation.

I saw that someone was talking about the flyback. This has nothing to do with the vertical compression fault! Most of the time, a defect in the area of the flyback will effect the high voltage, focusing, and maybe some width problems.

I strongly recommend, you give the set out for proper service, rather than tear in to it yourself. There are some very serious safety concerns, not only with the high voltage, but also with the main voltage distribution within the set. Also, there is the responsibility for safety hazard concerns when changing parts, and make soldering on the circuit boards.

I have been in the TV service business for a good part of my working life, so I know what I am talking about. On a number of occasions, I have seen customers injured badly from trying to service their own sets just to see if they can save a few dollars.

[Sam Goldwasser]

Well, no where does he say anything specifically about vertical collapse, just that it behaves the same as when it is turned off. That could be flyback or secondary power supply related.

I agree with your warnings though.

--- sam | Sci.Electronics.Repair FAQ Mirror:

Repair | Main Table of Contents:

+Lasers | Sam's Laser FAQ: | Mirror Sites: Note: These links are hopefully temporary until we can sort out the excessive traffic on Repairfaq.org.

Important: Anyth> This sounds like some components in the vertical deflection area have become

[BinaryBillTheSailor]

Many operating voltages for other circuits are derived from the flyback, and it is a very commonn source for these sorts of faults. The weight of the component leads to ring cracks at the connections, and intermittant problems such as the one the OP described. His vertical collapes is accompanied by the entire set shutting down. It's entirely likely that he has a cracked connection to his flyback.

Basic troubleshooting tip: When you hear hoofbeats, look for horses before you look for zebras.

BB

[Steven]