#16
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#17
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These old 42" Plasma sets rarely make more than $80 - $100 here.
LG Plasmas (and many other brands use LG panels) of this generation and earlier often have tired/worn out panels. You will still get a picture, but there will be random red dots everywhere that are very noticeable on dark scenes. Sometimes you can tweak them a bit and get a usable picture, sometimes there is no happy medium - Adjust far enough that the red go away (or at least are minimal) and you get dark dots on bright scenes. IPM replacement is not easy. It's a multilayer board and the ground pins will soak up all the heat without budging. Preheating the board and low temp solder help. I don't spend any money or much time on these kind of sets anymore - they're just not worth it. If I don't have a good used board available (that I pulled myself from another junked set, not from ebay) I don't bother. |
#18
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#19
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A little over a month ago, you faced the same dilemma with a Westinghouse 32 " set, where the cost of boards and other parts approached or surpassed the value of the set.... how did that work out for you?
jr |
#20
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And the biggest problem is that with these flat panels is that its hard to know whether or not they'll be worth fixing or not unless you take them apart and get a good look at the insides and when I see a Flat Panel in the salvage bin at work its not like they're gonna let me take the TV apart to see if its got blown capacitors in the power supply before I buy it off the salvage to see if I want to buy it or not, that's kind of what the repair business is all about, though isn't it, you're taking a chance that something may or may not be worth fixing to sell, its not just flat panel TVs that are that way, but also the old CRT TVs are that way as well and so are the old radios, when you buy something that's in unknown working order to fix it up and resell it, you're taking a chance that it may turn out to be a piece of junk that's not worth your time. Last edited by Captainclock; 06-15-2016 at 02:52 PM. |
Audiokarma |
#21
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https://www.amazon.com/SainSmart-Poc...ords=esr+meter Or a nicer looking box wih some handy short clip leads: https://www.amazon.com/Huhushop-Tran...ords=esr+meter Either one of these, properly used, should substantially improve your chances of finding bad caps on these sets... bulged and oozing appearance does *not* tell the whole story. just my 2 cents, jr |
#22
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__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#23
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I'll admit that I probably should invest in one of those ESR Meters, but then again like I said if its only 15-20 dollars you're probably going to be paying for something that's of poor quality build wise because that's usually the way it is in the electronics world, the cheaper the price is, the lesser the build quality and thus the more likely it is that it will be dead in about a year or 2.
Well I broke down and ordered an ESR Meter, and its was one that was in a case already. it was $35 but I figured it would be worth it, because it also had Mosfet, Transistor and resistor tests on it as well besides ESR Tests for Capacitors and it can test capacitors in circuit. And Jr. Tech, the ESR Meter I ended up getting was the one that was in the second link you posted in your post on here. Last edited by Captainclock; 06-17-2016 at 05:38 PM. |
#24
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I suspect that you will be pleased when you discover all that the tester can do. If you have not seen it yet, here is a link to a YouTube video of a short demonstration:
https://m.youtube.com/watch?v=b3dPBnYixs4 Contrary to his opinion, I find the ZIF (zero insertion force) socket to be very useful... about a month ago I went through a bunch of random semiconductor devices that were just thrown into a coffee can over the years and sorted out npn, pnp, fets, scrs, thyristors, diodes... very useful device! Here is a pdf by the original desiger... likely more than most need to know, but an interesting read nonetheless: http://www.mikrocontroller.net/attac...er_eng104k.pdf jr Last edited by jr_tech; 06-18-2016 at 01:01 PM. Reason: add second link |
#25
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OK so when measuring a capacitor's ESR rating what kind of measurement should I be getting if the capacitor is good, and what kind of reading should I get if the capacitor is bad? I'm wondering because I'm going to see If I can take another crack at that Westinghouse TV. |
Audiokarma |
#26
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000
Last edited by andy; 12-07-2021 at 04:18 PM. |
#27
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Depends on the size, voltage rating of the capacitor and quality of the capacitor, but lower esr is better. I printed out this scale as a guideline, and find it useful.
http://www.electro-tech-online.com/a...003-jpg.84737/ It is also useful to compare readings to those taken on a new good quality capacitor of the same size and voltage rating. On large capacitors, say under one tenth of an ohm or lower, you may need to zero out or just subtract the test lead resistance to get a better reading. jr |
#28
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#29
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Well I think I might of found one of the faulty capacitors in the westinghouse TV that was causing it not to power on, it was a 150MFD 450V electrolytic capacitor that measured at about 135 MFD and ESR measured at a whopping 8.5 ohms. So I think that might of been why the TV wasn't powering on considering it was the main filter cap for the power supply, at least I think that's what it is.
EDIT: I retested the capacitors again, and there were a few capacitors that did actually test off from where they should of been, so it seems I will have to replace some capacitors on the power supply board for the westinghouse tv. C46, C45, C59, C49, C11, C69, and C17 are the ones that measured unacceptable. Last edited by Captainclock; 06-19-2016 at 05:10 PM. |
#30
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I have even seen new (cheap) caps that were about 2 times the value stated on the chart and they seemed to work ok, while higher quality brands usually beat the chart number by a significant margin. jr |
Audiokarma |
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