Hi guys. I have been lurking around here for a while and always found this forum helpful, but finally couldn't find an answer to my problem without posting. I got this LG TV off craigslist for 40 bucks thinking that when I'd pop it open I'd see swollen caps all over the place. WRONG! Maybe I'm missing something, but I don't see any physically bad caps. I beleive the issue is in the power board which is where I am looking. I fixed a Vizio last week for a friend with two bad caps and thought I could take on this job, but I'm not sure anymore! I really want to get this thing running ASAP, but don't know if the problem is what I think it is. I don't mind replacing all the caps in the board if that's what it takes, but I could really use a little help here. I don't want to replace the whole board because that's over 100 bucks and at this point I don't even know if that;s the issue. Oh by the way the ISSUE with the TV is that it runs for a little while (perfectly fine) and then just shuts off. Sometimes it comes back on, sometimes it just doesnt want to come back on for a little while. According to some guy on youtube, his TV was doing the same thing until it finally wouldn't turn on at all (I didn't hit that stage yet), and he had swollen caps. Any help would be appreciated. Thanks
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Re: LG 50PC3D shuts off... bad caps?
Okay after staring at the thing for two hours, I may be going crazy, but I think I see a few caps starting to go bad. They are a pain to get a picture of, but is this one on its way out? The top isn't completly flat, but the thing isnt bursted yet. Let me know. Thanks!Attached Files -
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Re: LG 50PC3D shuts off... bad caps?
Those caps are fine.
Sounds like the extremely common AC detect issue with LG plasmas.
There should be a pin on the connectors going to the main video board called AC-DET.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PC3D shuts off... bad caps?
Is there any other name for it? I'm looking around where the power comes in to the TV, but honestly don't know what exactly I am looking for. If you could clarify that would be great. Also, what would be the fix if that is the problem (and how do I confirm). Thanks for the quick and helpful response!Comment
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Re: LG 50PC3D shuts off... bad caps?
Are there any labels on the PSU indicating pin names, e.g. 5V, 19V...Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PC3D shuts off... bad caps?
Ah yes I do see pins for those voltages... top right of the board if you look at my picture of the board.Comment
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Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PC3D shuts off... bad caps?
Here it is. Let me know if you need more pictures.Attached FilesComment
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Re: LG 50PC3D shuts off... bad caps?
Ah - okay - on this one they call it AC-D for some reason.
You will need to install the PSU in the TV with all connectors connected as they should be. Then, plug it in and check the AC-D pin with your meter. If it goes low when the picture goes out, this is your problem.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PC3D shuts off... bad caps?
Okay I will test that out in a bit. Should I be looking for a specific number or anything? Also what would be the fix if that the problem.Comment
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Re: LG 50PC3D shuts off... bad caps?
It should be either 3V or 5V if running, and drop down to nearly zero when it fails.
The fix involves applying a little bit of solder across two pins on an optocoupler - the consequence being a "click" heard from the speakers when the unit is unplugged.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PC3D shuts off... bad caps?
Alright, I can solder, I just don't understand where. We'll figure it out though I guess. No parts would be needed?Comment
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Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PC3D shuts off... bad caps?
the only way to test it is if I don't plug the connector for that in. Will I still be getting video or am i missing something?
Also which terminals exactly am I touching my meter on... one goes on AC-D and the other?Comment
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Re: LG 50PC3D shuts off... bad caps?
Solder a thin wire at the bottom of that pin, or just wrap some wire around the bottom of the pin. Or solder the wire on the bottom of the board (on the other side) where that pin is soldered through board.
When you press the connector over the pins it should keep the wire in place.
Hell, you don't even need to solder. If you're careful you can just use an insulated wire, strip a bit at the end, put the wire on the back and use some insulating tape to make the copper from the wire stick over the pin solder, without touching the other pins solder.
That should get you access to the pin. A Ground pad or pin should be available around that connector. Use same for the ground, solder a wire on the bottom of that connector on the other side of the board. Or have a look at where the trace for the GND pins go... it looks like one of those jumper wires in front of the connector is gnd (at least one end terminates right where the GND label is).
No, you probably need to have all the connectors plugged. I don't have experience with this TV but it makes sense.Last edited by mariushm; 08-10-2012, 09:10 AM.Comment
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Re: LG 50PC3D shuts off... bad caps?
Ah that helps... Thanks! so should i just use the first ground below AC-D?Comment
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Re: LG 50PC3D shuts off... bad caps?
Look on the other side of the board.
If that metal wire (jumper) connects the two GND pins, then you can simply put the multimeter probe on the wire outside the connector.
If that jumper wire is not connected to ground, ignore it.
Either wrap a thin wire around the pins for AC-D and GND or solder insulated wires at the bottom of the board on the pins.
If you go with wrapping a thin wire around the pin, you might find it easier to wrap wire around the two GND pins on the connector on the right.
When you push the connector in the socket, the wires should stay pressed there making contact, good enough contact to make measurements for a short period.
It doesn't matter what GND pin you use, GND should be the same in all connectors.Comment
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Re: LG 50PC3D shuts off... bad caps?
On most sockets you can get the probe down next to the wire and touch the top of the hollow pin in there or there is a hole in the side of the socket you can see the pins through. - easier than wires if you can do that - Id use a ground screw for the black probe.
You may need a helper -Whilst testing get someone to a) plug it in and b) switch it on and note the voltage recorded in both stages and again when it goes off.Please upload pictures using attachment function when ask for help on the repair
http://www.badcaps.net/forum/showthread.php?t=39740Comment
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Re: LG 50PC3D shuts off... bad caps?
Okay so i ended up just soldering wire to it and got some results. I did notice a voltage drop before it kicks off, but don't know if it's enough to do it. When plugged in and off, it gets 4.8 volts. High 4.7s when running, but as soon as it goes down to 4.74, it kicks off.. unless the voltage comes back real quick. Does that help diagnose the problem? please let me know. Thanks!Comment
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Re: LG 50PC3D shuts off... bad caps?
I just tried it again and noticed that it even goes down to 4.6x for a brief second, but always shuts off if it goes below 4.74. I was re-reading the previous posts and it seems like I should have seen the voltage drop all the way to 0. Could this still be the problem or should I be looking elsewhere?Comment
if it turns out to be the problem. Only a bit of solder.
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I know I've been a little scarce lately (like the last 2-3 years), but I'm still here and still doing my thing with fixing PSUs.
For today's considerations, I have a Seasonic B12 BC-550 [A551bcafh] 550 Watt ATX power supply for you (click on links for full size images).
https://www.badcaps.net/filedata/fetch?id=3591771
https://www.badcaps.net/filedata/fetch?id=3591772
It's a modern ATX unit with fixed (non-modular) cables and an 80-plus bronze certificate. Here's the label:
https://www.badcaps.net/filedata/fetch?id=359177... -
Hello,
First, I am a complete noob with high voltage stuff. I'm learning, but I need help by someone looking over my shoulder.
I recently came into posession of a Heathkit IO-4205 5MHz Dual Trace Oscilloscope. The documentation is copyright 1978. I'm told it works.
I opened it up to check the caps before I applied power, and found the following black caps and wanted to know what they were. They are on the power supply board. I was able to read the name and model and came up with, "Nytronics 162J-1, 0.1uF, 20% tolerance, 2000VDC."
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Hello!
I have two projects on my work bench. One is a friends dead JBL Xtreme speaker with a blown voltage regulator and corresponding bulged and shorted cap. That cap has clear markings so I know what replacement I need for it.
The other project however is a whole different deal. It's a Zoom 9000 guitar effect from the 90th that has developed a devil hound howl when there is no input from the guitar. I'm guessing caps problem. So, since I don't really use this effect anymore I thought it would be a perfect project to learn on.
I have studied the board and... -
I'm trying to repair two old VCRs, they both have bad caps. One has leaky ones, the other would barely run until I subbed in some caps from another power supply I had laying around (though they are the wrong values). This vcr works for an hour or two, but then the power supply starts whining and the picture gets lines in it. I didn't replace all the secondary caps, so another voltage might still be problematic, or the values I used are too far off.
I've been on mouser and digikey but the options are a bit overwhelming. I just need some new ones that will work. They don't need to be top quality,... -
Good evening
I recently aquired a rev 1.1 Gigabyte 60XT, and was suprised of the amount of leaking caps for a motherboard of the P3 era. Especially the way the 330µf caps seems like the housing discolored even.
Now, there are some 3300µF 6.3V KZG series around the CPU. Would it be OK to replace them with something like EEUFR1A332 ? (Panasonic FR 3300µF 10V). Or was this board designed around very low ESR caps?
But I was also suprised about the bigger boys, which are 330µF 25V.
Could it be they used 25V caps because they were cheaper / available at that time?...
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