GolfVenture Posted May 22, 2013 Share #1 Posted May 22, 2013 Are Flat Screen TVs as dangerous to work on as the older picture tube TVs? I'm thinking not but I figure someone here would know. My flat screen powers on but no picture. All the lights are on as normal. No response from the input, channel, volume and menu button. Sound is coming thru my sound system which is independent from the TV. Once on the power will not shut off. By habit we normally use the manuel power on/off button on the TV. Beside that all functions are controlled by the remote. Anyone have any experience with thses flat screen especially the Vizio? Link to comment Share on other sites More sharing options...
spike13 Posted May 22, 2013 Share #2 Posted May 22, 2013 i had an lg that would lose the pic after a couple min the sound worked the lights would stay on just would lose pic it was almost 4 yrs old had extended warranty from best buy they decided to scrap it Link to comment Share on other sites More sharing options...
rstacy Posted May 22, 2013 Share #3 Posted May 22, 2013 Many Vizio and Vizon TV's have been failing in this way. The most common solution is to replace your main board. Buying a new one from the manufacturer is quite expensive and the delivery time is quite long. The method I used was to post the model number exactly as it is posted on the board and do a search on Ebay. Set your search for least expensive + shipping first and you will save a lot of time finding your matching power board. The LCD itself is not likely to be dead, and the backlight is usually good for quite a number of years. These boards can be had for somewhere between $45 to $175 on average, and have usually been tested for defects. I also used a repair service that takes your board and sends you out a verified replacement. Check out youtube. They have a number of videos that cover the replacement procedure. Ray Link to comment Share on other sites More sharing options...
GAWildKat Posted May 22, 2013 Share #4 Posted May 22, 2013 I was given a flat panel tv last yr that wasn't working. The person who gave it to me had already replaced it and knew we didn't have one to use. If you can replace parts and/or build a pc/laptop from scratch you can work on flat panel tvs. It's a computer with a screen in one package. Often the powerboard or mainboard go on these tv from a power surge. Sometimes you can get away with replacing the fuse on the powerboard if the capacitors aren't blown. Usually a cheap part at Radioshack. Once you find the part number for the boards it's easy to find a site that sells the parts new. The Sharp TV in my bedroom needed the powerboard replaced, was $60 with shipping for a new board. If you need help finding the parts online let me know. Tricia Link to comment Share on other sites More sharing options...
etcswjoe Posted May 22, 2013 Share #5 Posted May 22, 2013 My 48" Vizio just started acting up with the remote not controlling the TV guess it would be along the same lines. Thanks for bringing up the question and everyone for the answers. Link to comment Share on other sites More sharing options...
GAWildKat Posted May 22, 2013 Share #6 Posted May 22, 2013 My 48" Vizio just started acting up with the remote not controlling the TV guess it would be along the same lines. Thanks for bringing up the question and everyone for the answers. In your case I'd go pick up a cheap tv remote at walmart and see if that fixes it before thinking it's the above issues. Link to comment Share on other sites More sharing options...
etcswjoe Posted May 22, 2013 Share #7 Posted May 22, 2013 In your case I'd go pick up a cheap tv remote at walmart and see if that fixes it before thinking it's the above issues. Tried two others no joy, you can uplug the TV for a little while and the remote will work once after it has been plugged back in. Link to comment Share on other sites More sharing options...
GAWildKat Posted May 22, 2013 Share #8 Posted May 22, 2013 Tried two others no joy, you can uplug the TV for a little while and the remote will work once after it has been plugged back in. Then that might be a mainboard issue, or the ir sensor is going bad. I'm not a tv tech, I just attempt it when the needs rise Link to comment Share on other sites More sharing options...
Snaggletooth Posted May 22, 2013 Share #9 Posted May 22, 2013 I hate to say it but from what I've seen the failure rate on the Vizio line appears to be high.. When I was doing my route with Hostess I had a big box store and I was always back in the shipping and receiving area. Never failed, there was always a flatbed cart with several opened and returned Vizio flat screens. I asked the manager one day what the story was and he said they were all returned by customers for failures and being returned to the supplier. Not a good sign. Link to comment Share on other sites More sharing options...
gmarshall Posted May 23, 2013 Share #10 Posted May 23, 2013 Have you changed the battery in the remote? Link to comment Share on other sites More sharing options...
GolfVenture Posted May 23, 2013 Author Share #11 Posted May 23, 2013 Have you changed the battery in the remote? yes, but I can take the batteries out of the tv remote and normally power on manually like I always do and the tv would work especially when the last time the tv was on was in tv mode. Link to comment Share on other sites More sharing options...
aharbi Posted May 23, 2013 Share #12 Posted May 23, 2013 Flat screens don't store high voltage as the old TVs to power a glass picture tube. None the less be sure to unplug the TV before working on it. I wouldn't "go inside" unless you had some idea of electrical/electronic workings. Also, after removing what you believe tobe the cover screws use a screw driver flat blade to work around the cover to unsnap it from the other half. First I would check the fuses on the power supply board. You will find two boards inside the one with the big parts and the heat shields is the power supply the other is the TV. The failure is most likely on the power supply board. Face down with back cover off http://i278.photobucket.com/albums/kk100/aharbi/Fixed%20computer%20display/IMG_1145.jpg Power Supply board http://i278.photobucket.com/albums/kk100/aharbi/Fixed%20computer%20display/IMG_1147.jpg Underside of power supply board. Notice the "cold solder" or loose connection. The happens over time from the components expanding & contracting from heating up and cooling off causes a weak solder connection to come loose. Take your time use a magnifying glass. http://i278.photobucket.com/albums/kk100/aharbi/Fixed%20computer%20display/IMG_1159r.jpg Carefully reheat the connection to let the solder reflow. You may but seldom need to add more solder. If you do, use solder for electronic stuff from Radio Shack NOT Home Depot. And keep the solder in the exact same spot, a shinny solder connection is a good one, not too long or the other connections will also start to melt (unsolder) http://i278.photobucket.com/albums/kk100/aharbi/Fixed%20computer%20display/IMG_1161r.jpg This may not be the problem. But if you're "dead in the water" it may be worth a shot. Hope this helps. Link to comment Share on other sites More sharing options...
GolfVenture Posted May 23, 2013 Author Share #13 Posted May 23, 2013 Wow, this is just what I was hoping, that someone would have a feasible suggestion. Similar to resoldering the air compressor board on a 1st Gen. I'm definately going to take a shot at it... I'll report back of my progress. 1st I'll have to get some help getting the tv off the wall. Another project to add to my to do list, only this one goes to the top if the list. Link to comment Share on other sites More sharing options...
GolfVenture Posted May 23, 2013 Author Share #14 Posted May 23, 2013 (edited) Well with a lighted magifying glass I did not come across what looked liked hair line cracks in the solder. What I did come across is a post unsolder. Maybe it was meant to be unsolder for it looks pretty clean that the solder did not break off. I did find a glass fuse. Took it out and took a flashlight bulb, a AAA battery and a piece of wire. The metal end of the bulb touches the + end of the battery. The wire end touching the metal side of the bulb. The other wire end touching the metal end of the glass fuse. The other metal end of the glass fuse touching the - end of the battery. The bulb lights ups, proving the fuse is good. Edited May 23, 2013 by Golf&Venture Link to comment Share on other sites More sharing options...
Dave Posted May 23, 2013 Share #15 Posted May 23, 2013 Hi I`ve had this same problem with a L G and a VIZIO tv and it is the main board (power) tthere is a relay not working ,stuck how I got mine to work was a heat gun, I would take the back off and warm up the board while it was plug in. getting it really warm and then turn it on reinstall back cover and I never turned it off again. svseral times I lost power I finally got smart and stop taking the cover off and just warming it through the vent holes in the rear cover. I had a loose solder connection on the power board and when board would cool off it would shrink and not connect. warming it expanded it to make connection. I ran the t v like this for 3 years then I found the power board on line for 100.00 replaced it still working fine I can shut it off now. I see a lot of this in the automotive field with all the computers in the cars. they do what they call a cold solder connection and see this failure all the time. not saying this is your fix but it was mine and worth a try. good luck. Link to comment Share on other sites More sharing options...
GolfVenture Posted May 23, 2013 Author Share #16 Posted May 23, 2013 there is a relay not working ,stuck how I got mine to work was a heat gun, I would take the back off and warm up the board while it was plug in. getting it really warm and then turn it on reinstall back cover and I never turned it off again. svseral times I lost power I finally got smart and stop taking the cover off and just warming it through the vent holes in the rear cover. I had a loose solder connection on the power board and when board would cool off it would shrink and not connect. warming it expanded it to make connection. I ran the t v like this for 3 years then I found the power board on line for 100.00 replaced it still working fine I can shut it off now. I know what a relay looks like for a vehicle, but what does a relay look like on a circuit board? I'm not much of an electrical person, but I do know how to take things apart and with some tutoring I'm willing to attempt a fix. Link to comment Share on other sites More sharing options...
GolfVenture Posted May 24, 2013 Author Share #17 Posted May 24, 2013 Thanks to "aharbi", he found on utube the exact sympton/problem of my exact same Vizio TV model and serial number. Only I did not want to pay $150.00 plus shipping for a new mother board. The problem is very common. The problem is the mother board has 3 specality retangular fuses and these fuses are tough to find. One of these fuses related to my specific problem and they go out about every 2 years. And mine did go out about 2 years ago only it was covered by the extended warrantee. This 250 volt, 1.5 amp fuse is a bit weak and looses it 1.5 amp rating and after about 2 years it blows again. This then reminded me of a fix I did on another curcuit board. Could not find anywhere the exact replacement but Radio Shack did have the fuse only in the standard glass type fuse. So I just bought an inline automotive fuse and solder it in. Bingo fixed. As I searched some more I can across a guy with the same exact TV , same exact problem and he fixed it like the way I'm going to fix mine. http://c.fixya.net/fixya20/uploads/Images/r_to_the_k.jpg All for less than $10.00. And when in two more years it blows again. The fix will be easy. Link to comment Share on other sites More sharing options...
aharbi Posted May 25, 2013 Share #18 Posted May 25, 2013 Way to go Brian! Good for you! The electrons don't care where nor how big the fuse is. Link to comment Share on other sites More sharing options...
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