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#1
01-05-2014, 08:13 AM
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What to do on used sets?
I was wondering if you guys could give me a list of things you do to used sets. Right now all I do is dust them out and tweek the focus control. Is there anything more to do?
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#2
01-05-2014, 08:20 AM
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Well, on a set that seems to be working properly, do a visual on the electrolytic capacitors and change any that are bulged and/or have pus coming out of them. I'm sure others here can chime in with more.
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#3
01-05-2014, 01:46 PM
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On TV's that I used to pick up to fix and resell, I'd sometimes replace any known capacitors that fail (mainly ones in the vertical and power supply circuits) and I'd also resolder any solder connections that looked bad (that was back when I could easily get $50-$75 for a 19" TV). Now, used TV's are not hardly worth the effort and a lot of the sets I find today already work. On the ones that don't work, I do as little as I have to do to get them going. I'm sorry; but, when a used TV only brings $10-$30, I'm not spending a bunch of time and money doing "preventative maintenance" just so it will last a little longer. When all these people are willing to spend are a few dollars on a TV; then, they can deal with whatever happens or spend hundreds for a new TV with a warranty. There's been times that I've paid more for broken TV's than what I can get for working ones today.
If it were a TV I was fixing for my use, I'd replace any common failure capacitors and resolder any questionable solder connections. I'd also adjust the CRT drive/bias and focus controls, if needed.
__________________
http://www.youtube.com/user/radiotvphononut
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#4
01-05-2014, 03:38 PM
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Sage advice given. What I would do is model specific.
An example is Sonys that get a cold joint in the hoz drive, blow hoz out, 2 power supply transistors & a fusable. You bet I will solder that need it or not. Other common things are best left alone til needed if ever. 73 Zeno 
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#5
01-05-2014, 04:30 PM
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| Audiokarma |
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#6
01-05-2014, 05:05 PM
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#7
01-05-2014, 05:21 PM
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It really depends on the set, stuff from the 80's will likely need nothing unless they use knobs, then they might need some cleaning and lube.
Some 70's sets like the Zenith CCII need to have the safety caps checked so you don't blow the tripler and CRT, and of course that era will need Pots and tuners cleaned. Preventive recapping is always an option, particularly in the sweep circuits where the most problems occur. You can prevent a Vertical IC or a HO Transistor from getting destroyed with some fresh caps. 90's and up just watch them till they die then toss em.
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#8
01-05-2014, 05:44 PM
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Several years ago, a guy brought me a mid '80's 19" Emerson color TV (the one with the chassis mounted sideways) for repair. He said he'd taken it to other shops and was told to throw it away. One shop told him, "throw that piece of junk in the creek and get you a real TV." This guy didn't want a new TV, he wanted his Emerson fixed; which, I fixed and he was happy. However, situations such as his are rare. Had he given me that same TV, I wouldn't have spent more than a few minutes and a few second-hand part on it because I would have been doing good to get more than a few dollars for a mid '80's woodgrained plastic cased TV.
__________________
http://www.youtube.com/user/radiotvphononut
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#9
01-05-2014, 05:47 PM
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One common problem I've seen on many later CRT TV's is lines and foldover at the top of the screen. This problem is almost always caused by a faulty cap in the vertical circuit. However, people will often run the set until the cap blows the vertical output IC. If they'd bring the set to me when it first started acting up, their bill would be cheaper and my job would be easier.
__________________
http://www.youtube.com/user/radiotvphononut
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#10
01-05-2014, 06:02 PM
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| Audiokarma |
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#11
01-05-2014, 06:52 PM
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She was talking and said "oh that CRT is about to go I know", and we aren't really supposed to talk as I'm in training, but I had to tell her, it might just be capacitors and end up being an easy fix, as the TV still had a great picture, nice and sharp and bright with vibrant colors. I don't know if she ever took my advice, but I hope she did.. Though it was a BPC TV from maybe 7 years ago, it's picture tube was strong. Just had foldover.
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#12
01-05-2014, 07:27 PM
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For as long as TV has been around, people mistakenly think that a vertically shrunken picture or no vertical deflection is a sign of a bad picture tube.
__________________
http://www.youtube.com/user/radiotvphononut
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#13
01-05-2014, 07:51 PM
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had a couple back in the lates 70s tell me emphatically,"when the front doesnt light,it a picture tube."they had an admiral solid state set with the good chassis but not so good crt.needed a tripler.i explained but they would have none of it.bought the set for 5.00.perfect cabinet and i installed a tripler the same day.set was a good piece but the crt fired up and wasnt as good as i like.installed a silvertone crt.looked really good but then along came a sylvania 25dmp22.it went in and what a picture!ran into the couple and they came and looked at the set.he noticed the dark crt right away."i told you it was a picture tube".couldnt disagree.
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#14
01-06-2014, 12:06 PM
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You never see non-remote or knob tuned sets there. They must scrap them.
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#15
01-06-2014, 12:16 PM
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All the usual adjustments get done on the later stuff ('70s color through the '80s sets).
Grayscale and drive adjustment/balance, focus adjustment, pincushion correction, purity, convergence, vertical linearity, horizontal size if adjustable, tuner strip alignment if desperately needed. All the little things which can take a decent CRT set and make it into a fine performer. Kind of obsessive with this.
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| Audiokarma |
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