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Old 4th January 2008, 04:35 AM   (permalink)
Default capacitor swap

Hi, I got a toshiba 42h83 tv with some bad aluminum electrolytic capacitors. My question is can I substitute them with tantalum capacitors? Would they be compatible or not. they are on the scan convertion module if that makes any differance.
thanks mopar r/t
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Old 4th January 2008, 04:56 AM   (permalink)
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Generally not a good idea unless you know how the ckt works exactly and what they might be subjected to. Electrolytics would be cheaper anyway.
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Old 4th January 2008, 05:05 AM   (permalink)
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Quote:
Originally Posted by speakerguy79
Generally not a good idea unless you know how the ckt works exactly and what they might be subjected to. Electrolytics would be cheaper anyway.
Thank you for the speedy reply
I didn't think it would be a good idea, but the guy at the parts store said it wouldn't matter. But I wanted a too make sure because I'm new to all this, but it makes sense to replace with the same parts.

Thanks again mopar r/t
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Old 4th January 2008, 08:01 PM   (permalink)
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mopar - I am less than an expert in this area but your problem description says "some bad electrolytic capacitors" - a cause for concern even if you find exact replacements.

Capacitors do fail as do other components but to fail together suggests that something - over temp, overvoltage, etc - caused the failures. Replacing the caps would likely not address those failures unless the cause were removed.
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Old 4th January 2008, 08:03 PM   (permalink)
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Maybe they dried out? Electrolyics can suffer that, so I would replace them, but should the problem arise again, take it to a TV repair specialist.
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Old 4th January 2008, 08:28 PM   (permalink)
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Quote:
Originally Posted by stevez
mopar - I am less than an expert in this area but your problem description says "some bad electrolytic capacitors" - a cause for concern even if you find exact replacements.

Capacitors do fail as do other components but to fail together suggests that something - over temp, overvoltage, etc - caused the failures. Replacing the caps would likely not address those failures unless the cause were removed.
stevez - Thanks for the reply. The info I"ve read and received from other peeps (not on this forum) stated that toshiba has a problem with those capacitors and all they do is replace them. I guess they may have been a bad batch or a poor design. But anyway thats all the repair shops I've talked to do.
I kind of know what you are saying, and also agree with you, but thats what they say.

mopar r/t
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Old 4th January 2008, 08:32 PM   (permalink)
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Quote:
Originally Posted by Krumlink
Maybe they dried out? Electrolyics can suffer that, so I would replace them, but should the problem arise again, take it to a TV repair specialist.
Thats what they said!!!! lol
The tv is around 5 years old and is always on. (Don't they have a 5000 hrs. life span?)

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Old 4th January 2008, 08:38 PM   (permalink)
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Electrolytics often go bad, you might be able to replace them with tantalums and the chances are it will be more reliable if you do.
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Old 4th January 2008, 09:51 PM   (permalink)
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Quote:
Originally Posted by Hero999
Electrolytics often go bad, you might be able to replace them with tantalums and the chances are it will be more reliable if you do.
As usual - not in my experience in TV's!

Replacing using good quality electrolytics, and using 105 degree ones (not the usual 85 degree), should easily outlast the TV.
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Old 4th January 2008, 10:04 PM   (permalink)
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Quote:
Originally Posted by Nigel Goodwin
As usual - not in my experience in TV's!

Replacing using good quality electrolytic, and using 105 degree ones (not the usual 85 degree), should easily outlast the TV.
I must totally agree Whenever you replace Electrolytic capacitors in a TV use 105 degree replacements.
Standard 85 deg are cheaper thats why the manufacturer uses them.
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Old 5th January 2008, 01:11 AM   (permalink)
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I think I'll use 105 deg. caps then. Thanks for all the great feedback. I've had more reponses and more quality answers here then anywhere else. Even the techs I've talked to haven't given me a straight answer.

Again THANK-YOU!!!!!!!

wonderful site

mopar r/t
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Old 5th January 2008, 03:41 PM   (permalink)
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Quote:
Originally Posted by Nigel Goodwin
As usual - not in my experience in TV's!

Replacing using good quality electrolytics, and using 105 degree ones (not the usual 85 degree), should easily outlast the TV.
I agree, but I've heard you complaining about unreliable tantalums and I'd disagree. I've never seen a tantalum go bad before, but I've seen plenty of electrolytics go bad in my time. I would think that your bad experiance probably be due to a dodgy Chinese supplier providing you with cheap knock-offs.
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Old 5th January 2008, 04:03 PM   (permalink)
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Quote:
Originally Posted by Hero999
I agree, but I've heard you complaining about unreliable tantalums and I'd disagree. I've never seen a tantalum go bad before, but I've seen plenty of electrolytics go bad in my time. I would think that your bad experiance probably be due to a dodgy Chinese supplier providing you with cheap knock-offs.
Not supplying me, I've never ordered any - all the TV manufacturers who used them soon stopped because of their appalling reliability. From a repair point of view first thing you do is look and see if there are any tantalums, change them all, and that cures most faults.

Electrolytics aren't wonderful, but they almost always go low ESR - tantalums almost always go short circuit.

Look in any domestic electronics, it would be EXTREMELY rare to find a tantalum - but for a year or two in the late 70's early 80's, they were everywhere (and going S/C everywhere).

The only place I've ever used a tantalum is as the timing capacitor in a 555, and that is one place I WOULD recommend them
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Old 15th January 2008, 04:10 PM   (permalink)
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I must disagree with you Nigel, about ELCO vs. TANTALUM. They both have their place in designing things. I think for the purpose mopar r/t suggested tantalum caps could be same if not better replacement. The main reason they don’t use tantalum is a PRICE. But tantalums are better for most applications if no need for really big caps. Also it is truth that tantalum caps are more prone to go short rather then low ESR but it really happens rarely, and not to mention that those caps you are talking about were lower quality then new made tantalum caps. On that board of mopar r/t, often addressed as Hyperboard or Hypermodul it happens al the time caps go bad and all one shoul do is to replace them. Since this are SMD caps however it might be a problem to find replacement SMD tantalum caps, but the caps he needs are 10uF 16 V and he needs about 10 pcs replaced.
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Old 15th January 2008, 05:16 PM   (permalink)
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Thanks for the reply Pitronix, I thought tantulum caps would have been a better choice at the beginning,but from all the answers I have recieved here have made me change my mind. I do have 1 question to ask, could I use a radial cap in they place, just trying to find different solutions for a small problem.

thanks Mopar r/t
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