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-   -   Black screen! Oh no! (http://www.videokarma.org/showthread.php?t=258783)

John James 07-12-2013 05:35 AM

Black screen! Oh no!
 
I've got a 40 in. Polaroid LCD TV. when I try to power it up I get a black screen. The audio is fine. When it worked right, the word "POLARIOD" would show for a couple of seconds and then it would go to the picture on whatever channel I was on. Now, sometimes the word POLARIOD just barely flashes and then the screen goes black. Does anyone have any idea what may be wrong?:scratch2:

Thanks for your time,

John

rlovison 07-12-2013 08:11 AM

Quote:

Originally Posted by John James (Post 3075471)
I've got a 46 in. Polaroid LCD TV. when I try to power it up I get a black screen. The audio is fine. When it worked right, the word "POLARIOD" would show for a couple of seconds and then it would go to the picture on whatever channel I was on. Now, sometimes the word POLARIOD just barely flashes and then the screen goes black. Does anyone have any idea what may be wrong?:scratch2:

Thanks for your time,

John

I have a Toshiba 32HLC56 that did the same thing. It's called "2 seconds to black." Info can be found here:

http://www.badcaps.net/forum/showthread.php?t=10419

My problem ended up being a bad transformer on the inverter board. I could have replaced the transformer but instead I found a used inverter board on eB*y for the price of one brand new transformer so I just swapped boards. Your problem could be as simple as mine or something more involved. Maybe someone with your make and model can give you more info.

Bill R 07-12-2013 08:33 AM

The floursent back lights are not coming on. Usually a problem on the inverter board. It should be the board the tubes connect to. There is a transformer for each tube I think. Dont hold me to it though. Someone on here is likely an LCD repair expert and may be able to help. The Polaroid sets did have some capacitor problems I have heard as well. So power to the inverter is also suspect.

John James 07-12-2013 08:55 AM

Thanks. I'll start checking those things that I can and hope its something simple as I have no background in this kind of thing.

Zenith26kc20 07-12-2013 09:47 AM

Capacitors fail rapidly on these sets. If it is one with the removable hatch in the back, it will reveal the module easier than most.
If caps don't repair it, keep in mind some of the Polaroid sets are devils to use, even with the correct remotes!
I have to say, I don't give them as much effort as other LCD sets as I find their picture a bit poorer than most.

John James 07-12-2013 11:02 AM

Quote:

Originally Posted by Zenith26kc20 (Post 3075505)
Capacitors fail rapidly on these sets. If it is one with the removable hatch in the back, it will reveal the module easier than most.
If caps don't repair it, keep in mind some of the Polaroid sets are devils to use, even with the correct remotes!
I have to say, I don't give them as much effort as other LCD sets as I find their picture a bit poorer than most.

I have been using this in my garage so picture quality is not of prime importance. It was working fine and then....:sigh:

Thanks for your time though.

John James 07-13-2013 09:49 AM

Good morning,

I tried the flashlight trick and there is a picture in there! :banana: Now how do I get it out? I'm assuming there is a problem with florescent lights?

Thanks,

John

rlovison 07-13-2013 11:09 AM

Quote:

Originally Posted by John James (Post 3075647)
Good morning,

I tried the flashlight trick and there is a picture in there! :banana: Now how do I get it out? I'm assuming there is a problem with florescent lights?

Thanks,

John

John,

The CCFL tubes might be OK though something on the inverter board might have failed. What model Polaroid is it?

John James 07-13-2013 12:36 PM

Quote:

Originally Posted by rlovison (Post 3075652)
John,

The CCFL tubes might be OK though something on the inverter board might have failed. What model Polaroid is it?

POLAROID 40" HD Widescreen TLA-04011C

Thanks.

rlovison 07-13-2013 03:50 PM

Here's an inverter board for a TLA-04011C set. Not sure if it's exactly what you have as the model number seems to be used on many sets having different size screens.

http://www.ebay.com/itm/POLAROID-TLA...-/190696895817

I'm not telling you to purchase it but now you know what to look for when you remove the cover from your set. Of course, unplug the thing first.

If you discover what model transformers are on the board (big rectangular things with coils of wire) you can than test them using a voltmeter in resistance mode. Hopefully someone on this forum has experience with your model television that can help you out.

John James 07-13-2013 08:18 PM

Quote:

Originally Posted by rlovison (Post 3075676)
Here's an inverter board for a TLA-04011C set. Not sure if it's exactly what you have as the model number seems to be used on many sets having different size screens.

http://www.ebay.com/itm/POLAROID-TLA...-/190696895817

I'm not telling you to purchase it but now you know what to look for when you remove the cover from your set. Of course, unplug the thing first.

If you discover what model transformers are on the board (big rectangular things with coils of wire) you can than test them using a voltmeter in resistance mode. Hopefully someone on this forum has experience with your model television that can help you out.

Thanks for the info and link. I've got to get the set off the wall so I can open it up. (Time for a call to my neighbors!:D) I'll keep in touch and let you know what I see.

Thanks,

John

John James 07-27-2013 10:40 AM

1 Attachment(s)
I finally got the set off the wall and opened it up. It is entirely possible that this connector (see picture, at top, white plug) was off when I took the back off. I did not have to unplug it like I had to do to all the others. If that was unplugged, that would explain why I had no back lights wouldn't it?

Thanks for your time,

John

John James 07-28-2013 09:50 AM

1 Attachment(s)
Update. I plugged the white connector back in and powered up the TV. The back lights came on for a second and went back out. When they were going out, I heard a bacon frying sound:sigh: that came from (I think) one of the black rectangular things at the top right of this picture. At the same time a little red light located to the left in the picture came on. Does this mean I have to replace this whole board, or just the rectangular what-chama-call it? BTW, I know next to nothing about soldering.

Thanks,

John

mstaton 07-28-2013 10:10 AM

Those are the HV transformers for the inverter. One is probably going tits up.

John James 07-28-2013 10:11 AM

Does that mean replacing the board?


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