My image wavers when it's hot, doesn't stay cool very long

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Sanyo dp50747 Plasma TV

50" Plasma TV by Sanyo released in 2007.

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jeffjeffjeff145 @jeffjeffjeff145

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发帖于: 2017年3月4日

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My image wavers when it's hot, doesn't stay cool very long

So my dad used to have this TV and it never had this problem till right before he gave it to me. Unless the room is freezing, the tv will get hot very fast and then the image will start to freak out. It happens with any input. It just has to be on for more than a couple minutes. And it has tons of space behind it. What's wrong with it?

This area seems to be the warmest

And these two are slightly warm.

However the metal itself below the boards is extremely hot.

I've also noticed the tv makes odd sounds the hotter it gets. They are quiet. But noticible.

Here is the other board.

(Sorry the photos are so dark.)

And final one.

I have also noticed on the casing for the tv, there are burn marks over where it would cover the left side panel, and right side panel. And in the direct center/top there is a burn mark as well.

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jeffjeffjeff145 have you removed the back of the TV to determine which part or what location heats up? Could be an issues with the power board. Let us know what you find and post some pictures of your boards with your question. Use this guide 在已经存在的问题里加入图片 for that.

由 oldturkey03 完成的 2017年3月4日

I have opened it and looked a couple weeks ago, but nothing seemed to be wrong with the wiring or anything. The screen and around the vents on the back just produce alot of heat. And once it gets hot enough, Horizontal lines travel up the screen. Turning it off and letting it cool fixes that but it takes awhile. How exactly is this TV supposed to stay cool? Is there a fan somewhere?

由 jeffjeffjeff145 完成的 2017年3月4日

Just checked and your model TV does not have a fan. Excessive heat is usually an indication of some component having failed. Turn it on with the back removed and see if you can narrow down what heats up. Post some images of all of your boards with your question. For that use this guide 在已经存在的问题里加入图片 Whenever something heats up like that you need to check the MOSFETS and Diodes as well.

由 oldturkey03 完成的 2017年3月4日

I will do that. It might take a day or two though. That TV is way too heavy for me to lift alone.

由 jeffjeffjeff145 完成的 2017年3月5日

Ok I've opened up the back however I know very little about circuitry. Where are all the boards located?

由 jeffjeffjeff145 完成的 2017年3月13日

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jayeff @jayeff

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发帖于: 2017年3月14日

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Hi,

One quick and dirty way to narrow down the problem area is to purchase a can of electronic freezer spray. If you use this with the narrow straw like applicator that usually comes with spray cans you can "freeze" individual components to see if the TV restores to normal picture. Do not flood the area, be sparing in how you apply it. You are trying to isolate the problem component.

Initially try to determine whether a component is "hot" or just warm to save spraying too many components. Place the back of your hand close (definitely NOT TOUCHING ANYTHING) to get an idea of the radiant heat being given off.

BE SAFETY AWARE! THE TV IS "LIVE" DO IT WITH ONE HAND BEHIND YOUR BACK (only half joking - that way you will not have one hand accidentally touching something live - which is bad enough - and the other touching something else that you shouldn't)

The ones covered in metal do run warm/hot, that is why they have heat sinks to disperse the heat. Remember electronics can run warm and even hot.

It may be trial and error but then again you may get lucky.

After freezing the correct component, the TV should behave normally. When the effects wear off it will return to being faulty so you can determine by freezing it again whether you have the correct one or not.

It might be prudent to have a mirror in front of the TV facing to the back where you are working. That way you only have to look up and over (or around) the TV to see if anything has happened when you spray.

Here is a link to what I mean. You may have to source something similar from your local electronics shop.

Do one or two components at a time, give it time to have an effect before moving on that way you will not be confused as to which one may be the problem

https://www.jaycar.com.au/freezing-spray....

SAFETY FIRST! Remember to disconnect the power before touching anything in the back of the TV

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I have the same problem with my Sanyo gets do hot that u put a fan on it while watching. Affraid if I left on when not there could catch fire it's so hot

由 Christine Shipway 完成的 2017年6月7日

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jeffjeffjeff145 have you removed the back of the TV to determine which part or what location heats up? Could be an issues with the power board. Let us know what you find and post some pictures of your boards with your question. Use this guide 在已经存在的问题里加入图片 for that. — oldturkey03
I have opened it and looked a couple weeks ago, but nothing seemed to be wrong with the wiring or anything. The screen and around the vents on the back just produce alot of heat. And once it gets hot enough, Horizontal lines travel up the screen. Turning it off and letting it cool fixes that but it takes awhile. How exactly is this TV supposed to stay cool? Is there a fan somewhere? — jeffjeffjeff145
Just checked and your model TV does not have a fan. Excessive heat is usually an indication of some component having failed. Turn it on with the back removed and see if you can narrow down what heats up. Post some images of all of your boards with your question. For that use this guide 在已经存在的问题里加入图片 Whenever something heats up like that you need to check the MOSFETS and Diodes as well. — oldturkey03
I will do that. It might take a day or two though. That TV is way too heavy for me to lift alone. — jeffjeffjeff145
Ok I've opened up the back however I know very little about circuitry. Where are all the boards located? — jeffjeffjeff145
I have the same problem with my Sanyo gets do hot that u put a fan on it while watching. Affraid if I left on when not there could catch fire it's so hot — Christine Shipway

oldturkey03 @oldturkey03 声誉积分: 781.7千 1.1千 893 2.3千 · Answer 1 · 2017-03-13T21:59:16-07:00

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oldturkey03 @oldturkey03

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发帖于: 2017年3月13日

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jeffjeffjeff145 the first board is your power board PSPF561A01A I'd expect that to be the warmest since it does most of the work. 2nd board is your Y-main board LJ92-01399A 3rd board is the LJ92-01398A X-Main Board. From what I can see the caps etc. look good. I am missing your main board, Ysus board as well as the buffer boards. Most importantly the filter board B10N2010A. take some power reading on the main board. Follow the block diagram for that. The waiving and sound distortion sound like a bad cap/IC problem will be to hunt down the proper board. You'll need a multimeter to check on some of the connectors. Let us know how far do you want to go with this. The heat coming of the panel is somewhat odd and would require more of an investigation as well.