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Please for the love of god do not change the tube. Picture tubes are large capacitors and are rather dangerous to play with.

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Please for the love of god do not change the tube. Picture tubes are large capacitors and are rather dangerous to play with.

 

Thanks Thomas, this is very true...i remember once I was modifying some cctv monitors with built in receivers to convert them into just monitors with line in and got a good buzz even though it was not plugged in. The tv had a charge to it. The monitor is a cheap all in one surveillance system that I had sitting around for ages.

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If its a line going from across the screen (left to right) in the middle, then it sounds more like the vertical deflection has gone, rather than the tube (although if left displaying that picture for a long period if could burn that line onto the tube...)

 

Could be a fairly cheap fault to fix if you have a cheap local tv repair man, but

you could find that the repair cost is around the same as just getting a new model, which would have a new warrantee also.

 

 

Dont try to fix it yourself unless aware of all the safety issues and dangers, tv's are very high voltage inside, even after being switched of for considerable periods of time.

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ps, if the line is going up and down the screen from top to bottom in the middle, then dont use it any more, as it will probably get worse faster, and could be dangerous. Possible a harder repair to.....

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9" BW Monitors are very inexpensive these days, less than 1 hours labour, id buy a new one before servicing it.

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As kensplace suggested, the scan has collapsed so that's possibly either the line output transformer or transistor (or driver circuit).

 

Not really a major fault for an experienced engineer, but most definately not a DIY job to fix.

 

As Thomas has already said no one should ever ever ever attempt to change a CRT unless they know what they are doing.

The High Tension circuit can kill a person in double quick time, and an engineer will always discharge the HT connection before doing anything else.

 

The charge can often remain at a highly dangerous level for a long time after the set has been switched off, so don't even think about trying to save a few bucks; it just ain't worth it!!

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I have repaired t.v.s in the past. It does not seem that long ago when every drug store had a tube checker with the red zone, yellow, and green zone. You shoved the tube in to the socket that matches, and set all of the dials, and pressed the big button. If it was in the red zone, you looked on the shelf above, and took the tube to the counter.

 

I have a question. Is there a particular color monitor that would be common among various retailers (even if branded under various names). I also wonder if they would have a capacitor kit.

This is common in the video arcade games. You order the cheap cap set, and if that fixes the problem you off, and making money again. If there is a problem, and you do not want to spend labor benching it, then you would just replace it. Most companies just grabbed a monitor out of a video game that was not pulling its weight.

 

Anyone ?

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discharging the crt isn't that difficult to do, basically you short the metal frame on the front of the crt tube to the aquadag connection on the side of the tube under what normally looks like a rubber suction cup. a jumper lead with 2 alligator clips and a thin screwdriver that slides under the rubber cup to touch the dag connection is all that is needed.

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You can also get nasty suprises from electricity stored in uncharged capacitors, and a risk of implosion if you accidently break the tube whilst inside the set. Plus the chassis can often be live on tv sets.

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Sounds like fun, for what a TV costs these days (very little), its easier just to buy a new one.

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A thin vertical white line is not the symptom of a bad picture tube. It is caused by a problem in the horizontal deflection circuit. Either the yoke, or most likely a bad transistor or other part there.

 

Do not attempt to replace the CRT unless you know what you are doing.

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I have monitors sitting out once in a blue moon and I scare the techs by hiding near by and making sssssssssssssssssssss noises making them think that they broke the tube and the vac is leaking out. One of the techs got even one day by sneaking up behing a rack, he lit a piece of cardboard, fanned the flame out, and let the "smoke" waif out. I just happen to power up the rack for the first time, and I smelled smoke, and I about broke my legs trying to shut off the power. I was a little miffed, but that was the best I have ever been "had".

 

Did anyone catch my faux pax? The vac was leaking out?

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