Need help replacing capacitor on Insignia LCD 32" - AVS Forum
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post #1 of 16 Old 02-26-2010, 01:39 PM - Thread Starter
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First off, I want to say thank you in advance to all who end up commenting or reading this thread.

I have a 32" Insignia LCD TV that recently started experiencing problems. Basically the picture would cut off after 5 minutes of watching (I use an HD cable box from Cablevision). I tried switching the HDMI cable out with another one and also tried the other HDMI port however the problem persisted.

After I did some research online, I got the impression that a capacitor was blown and it seemed a relative easy repair (however I do not have any soldering experience).

I opened up the TV today, prepared to see some popping caps and got ready to replace them, unfortunately the situation appeared a little worse than I initially thought it would be.

I

As you can see, there is a gooey tacky substance that has "leaked" from an "exploded" capacitor. This is obviously not what I was expecting.

Here is a picture of each of the caps with the leakage:



The pictures aren't great but this cap seems to be obvious where the leaking is coming from.



This picture however, it does not seem as obvious where the leaking is coming from. It seems to be coming from the copper coiling area (sorry not familiar with electronic parts).

My question is, what steps do I need to do in order to fix my problem? Someone mentioned getting Electric Clean to get the tacky **** off (is this safe if it touches the other electric components). Once that's off I'm assuming I would then desolder using a desoldering braid (which I'll try and find a DIY on youtube for). Then I'm guessing I would pop the cap off and place a new one on.

When replacing the new cap, I've read that as long as the uF is matching, that the wattage can be higher, is this correct?

Does anyone have a good DIY reference to use for this?

Thanks in advance!
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post #2 of 16 Old 02-27-2010, 10:04 PM
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I hate to disappoint you.... you should leave electronics and capacitors' replacement to a Service Technician. The "Tacky-Gooey substance oozing from capacitors" is nothing more than glue. It is used to prevent any movement / vibrations during transport from factory to consumer home.

The large capacitor is rectified mains' smoothing cap - that is lethal DC voltage!. Stay away from that one while TV is powered ON. Give it a minute or so after TV’s been switched OFF before you touch it.

The coil is filter coil to get rid-of high frequency switching artefacts. That particular coil has the glue on to prevent possible movement - the coil could touch the grounded heatsink near by causing short circuit - hence the glue blob between coil and PCB.
If you really want to go ahead and start replacing the caps, large uF value and voltage ratings are both okay… that’s a switched mode power supply – hence the more important to pay attention would be to select the cap that is designed for high frequency switching / smoothing applications. Otherwise, the caps will overheat, dry and eventually bulge or explode – like in samsung TV’s!

Boky
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post #3 of 16 Old 02-28-2010, 08:35 AM - Thread Starter
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Thanks a lot for the advice.

So in my haste I actually removed all the glue and now am left wondering what to do next. None of the caps appear to be bloated or exploded (except for the ones in my misdiagnosis.

Can you provide any recommendations on how to test the caps to see if they're failed or not? I have had the circuit board out for a few days now so I'm assuming any power leftover in the board is done (I have actually touched the large cap you mentioned with the lethal wattage since then and I am still alive to write about it haha).

I believe the circuit board shown in my post above is for the power supply. Is there any chance that all the caps are fine on this circuit board but the input circuit board could be screwed up?

I appreciate any advise and direction as I am not in a position to spend $400 on a new TV at this time.

Thanks again!
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post #4 of 16 Old 02-28-2010, 09:18 AM
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Quote:
Originally Posted by tbonfig View Post

Thanks a lot for the advice.

So in my haste I actually removed all the glue and now am left wondering what to do next. None of the caps appear to be bloated or exploded (except for the ones in my misdiagnosis.

Can you provide any recommendations on how to test the caps to see if they're failed or not? I have had the circuit board out for a few days now so I'm assuming any power leftover in the board is done (I have actually touched the large cap you mentioned with the lethal wattage since then and I am still alive to write about it haha).

I believe the circuit board shown in my post above is for the power supply. Is there any chance that all the caps are fine on this circuit board but the input circuit board could be screwed up?

I appreciate any advise and direction as I am not in a position to spend $400 on a new TV at this time.

Thanks again!

1. If you are asking how to test the caps, Stay away... You are asking for trouble...

2. Go to freecycle and or craigslist and get a basic tv until you can afford a new one... Believe it or not, people give away CRT tv's... I will be getting a new tv soon and would be GLAD to give it away and it's a 26 Panny WS HD 1080i... does the job.. So I assume if you go to those places, Someone would be willing to dump their stuff for free in your local area
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post #5 of 16 Old 02-28-2010, 11:22 AM - Thread Starter
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Ok thanks for the advice.

I am still going to attempt to fix my 700 TV before just dumping it and waiting to get a new one.

If anyone can provide more technical and not economical advice, it would be appreciated.

Thanks
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post #6 of 16 Old 02-28-2010, 01:33 PM
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Not so sure if busted capacitors are your problem, you would likely have seen some "bulging" and possibly some capacitors that released their fluid, and in those pics i haven't seen any.

Replacing a capacitor properly is not easy for those who have never done it before. Perhaps a local electronics repair shop can inspect the internals for you? Let them know that you are willing to pay for their inspection time, but that you may want to complete the repair yourself. You may as well get an estimate for the full repair while they are there, then inquire what it is they are "repairing" or replacing.

You might get lucky and find the defective part online, or on ebay.

Good luck either way.
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post #7 of 16 Old 02-28-2010, 01:48 PM
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There's a popular trend here of recommending people replace their own capacitors. I think it's ill advised and should only be done by people that know what they are doing. Large capacitors can be dangerous.

Back off man, I'm a scientist.
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post #8 of 16 Old 02-28-2010, 07:40 PM - Thread Starter
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So I completely disassembled the TV this morning, checking the power supply board and the "input board" (not sure of the exact name for it). There did not appear to be even the slightest thing close to a "bulging" or "exploded" capacitor. Especially after confirming my suspicion that the tacky stuff was not from a capacitor and it was some adhesive.

Does anyone have any recommendations on troubleshooting this on my own? After I reassembled the TV, it turned on and worked for about 10 minutes this time, however it still ended up shutting off in the end.

I can only imagine that to bring it to a tv repairman that it would cost about $75+/hour and that's not really an option for me right now.

So in summary:
1. I do not believe a blown capacitor is the issue
2. I still need help :-(

As mentioned earlier, any and all help is appreciated.

Thanks!
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post #9 of 16 Old 02-28-2010, 07:51 PM
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if you cannot find any visible damage to components on the circuit board you will not be able to fix the TV without having a service manual that likely does not exist for an insignia TV anyways and you will also need proper test equipment and experience and know how to perform these tests.

junk the thing its a garbage TV and let it be a lesson about saving a few bucks and buying a house brand TV rather than a good brand.

as others have mentioned already people pretty much give away their old monster CRT's

A buddy of mine picked up a Sony 57" 1080i CRT RPTV for free a week ago, there's plenty of cheap/free TV's out there you just need to find one

If you're a gamer or interested in using an LCD TV as a primary monitor take a look at my thread on
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post #10 of 16 Old 02-28-2010, 07:54 PM - Thread Starter
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Ha... I do appreciate everyone's recommendations to just buy a new TV or pick up an old CRT, but I do like to fix things myself and hate the thought of a $500 TV in non-working order after 2 years...

after doing some investigating I've found some sites mentioning a bad inverter... anyone care to comment on this option?
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post #11 of 16 Old 02-28-2010, 07:54 PM
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$700 for a 32" Insignia, OUCH. Talk about "got to have it when it first comes out" early adopter tax...

Check out shopjimmy, sometimes they carry the 3rd tier TV parts.
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post #12 of 16 Old 02-28-2010, 11:00 PM
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tbonfig-

Welcome to AVS Forum. I hope you are aware that not all requests for advice or help here result in non-relevant or off-topic answers as you have got here mostly, so far.

First of all, since you do truly want to try to fix your LCD TV, you should do some basic electronics experimenting and testing before trying to jump into something like a flat-panel TV. Otherwise, it is kind of like going from a desk job to trying to fix a Ferrari, without starting with bicycles, lawn mowers, or Fords first. The mistake with the capacitor glue is a good example of reading just a bit about electronics and then making a reasonable, but mistaken, observation of what looks like "bad" parts.

If you do want to try to go into that TV quickly without trying to fix a few radios, amplifiers, or stereos first, then you should at least read about (and buy) a digital multimeter, and read about (and understand) a "hot chassis" and switching power supplies first. This is the kind of stuff that is dangerous. Honestly, trying repair of equipment like LCD TVs is probably not worth the effort unless you also want to start doing more than just your one set, and in that case it is worthwhile to learn the basics as I described above. If it does interest you, it is in fact a good skill to learn.

Regarding the inverter, that is the circuit that produces the high voltage (remember my comment about "danger" above) needed to light up the back of the LCD panel (there are some very thin/flat fluorescent light bulbs there). If it was bad, first of all, your sound would probably still work when the screen went blank; does it? Testing the inverter would require a high-voltage test meter, and careful understanding of how to use it. Again, you can learn all of this, since you like to fix things; are you willing to put in the effort? Let me know if you decide to look into it some more, and good luck.

Chris

"It's [expletive] lame to watch Jaws, a film that uses the 2.40 ratio as well as any ever produced, in the wrong format on HBO." -Steven Soderbergh, Oscar-winning director

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post #13 of 16 Old 03-01-2010, 03:36 AM
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Quote:
Originally Posted by tbonfig View Post

Thanks a lot for the advice.

No worries.

Quote:


So in my haste I actually removed all the glue and now am left wondering what to do next. None of the caps appear to be bloated or exploded (except for the ones in my misdiagnosis.

Can you provide any recommendations on how to test the caps to see if they're failed or not? I have had the circuit board out for a few days now so I'm assuming any power leftover in the board is done (I have actually touched the large cap you mentioned with the lethal wattage since then and I am still alive to write about it haha).

Unfortunately, capacitors are not easy to measure. There is almost always more than one capacitor doing power supply rail decoupling - hence you'll be measuring added capacitance of two or more caps... the only way to measure the capacitance is to remove the cap in question and then check capacitance.

Quote:


I believe the circuit board shown in my post above is for the power supply. Is there any chance that all the caps are fine on this circuit board but the input circuit board could be screwed up?

The board is switched mode power supply and inverter in one. The transformer with multiple litz copper windings is high frequency / high tension transformer for CCFL's. If you want to do something about the TV, I suggest you to try and get the circuit diagram. See if you can figure things for yourself, and if not - get the service technician to fix the TV for you.

Quote:


I appreciate any advise and direction as I am not in a position to spend $400 on a new TV at this time.

Thanks again!

I understand, get the Service Manual and see if you can figure thing or 2 by yourself. I am happy to help you further, but you must do some reading / learning first....

Boky
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post #14 of 16 Old 03-03-2010, 04:46 PM - Thread Starter
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First of all, this is an amazing forum. Thanks for your time and input.

I have since put my television back together and... it didn't explode! However its still not fixed.

i went into serious troubleshooting mode tonight and this is what I've come up with:

My tv has two HDMI inputs, a coaxial cable input and component cable inputs (amongst others).

I have now tried using 3 different HDMI cables with each of the ports and tried using my HD cable box, my laptop and my PS3 as different input types.

Initially, my test was with one of the HDMI cables and my HD cable box. As mentioned earlier, the TV worked for about 5 minutes and then turned into a black screen with the source (HDMI Input 2) pulsating on the screen. This continued as if the TV was trying to detect the input and then a code was thrown up "Unknown Input Timing."

When I had originally contacted Insignia (which is one of the poorest customer services response companies I've ever experienced), I mentioned this code and no one knew what it meant, surprise surprise. Unfortunately, even when I contacted my local TV tech repair guy he didn't know what the code meant and told me it would prob cost about $250 for him to get a new board and put it in.

I had attempted previously with the component cable hooked up through the cable box... when the picture ended up cutting out (which it inevitably did again), the audio still worked. So I don't know what this means.

Someone asked above if I received sound when my video cut out. Well the answer is, if I'm testing using the HDMI cable no, and I'm assuming its because the HDMI cable delivers both the audio/video that is the reason why not. However when I'm testing using the component cables then the audio still works when the video doesn't.

Ok so here's the next doozy. I decided to try hooking the coaxial cable straight from the wall into the TV.... IT WORKS! However when I try to run the cable into the cable box and then from the cable box into the TV it does not work.

What does this tell me now?

Am I any closer to finding a solution?

If I was a guessing man I'd say that my input board is bad, however that would just be my uneducated guess.

Suggestions ladies and 'gents?
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post #15 of 16 Old 03-05-2010, 08:52 AM - Thread Starter
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please help :-)
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post #16 of 16 Old 09-07-2011, 11:03 PM
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Soooo .. Do you have a bad cable box?
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