LCD flat screen picture will run for 20-30 minutes and then no picture. Sharp LC 32D40U 2 years old.Sound live and channels will change (no channel indicators)
Had the same problem and glad I found this site. Picture would go black, but sound and faint image would still be on the screen if you looked real close. We keep thinking we pushed a wrong button on the remote and changing a setting.
Took the back of the set off and a little 3 or 4 wire connector was basically unplugged near the power input. Plugged it back in, put on the cover and back in business.
Thanks for the helpful posts. The economy is bad, but a dead TV is worse!
-TB
Commentor on March 07, 2008 seems to have the fix. My LC-32d40u has had the same problem for a year now. To temporarily fix it, I turn off the TV and Bang the back of it really hard. Then turn it back on and it will work again for a few more hours. Which basically creates friction on the contact points and creates a better connection. I opened up my TV today to try cleaning the contacts as mentioned above. The "ground points" where the inverter board met the plate, as the commentor mentioned on Mar 07, 2008, were worn out and turned from a silver to a black on those spots. This is probably due to me banging the TV and creating friction that rubbed some material off the plate.
I put the tv back together and it turned on okay. Will have to check next couple days to make sure, but this is probably the reason for this problem, not overheating. I do not think a new inverter board needs to be replaced since it seems to be only a temporary fix of a few months from other commentors. Changing out the inverter board probably creates better contact temporarily and so fixes it sometimes or maybe just temporarily depending on luck.
Try shining a very bright flashlight on the screen. Can you see the image (but VERY VERY dark)? If so, either the inverters or lamps are bad, which are only sold with the LCD Panel as an assembly, which is VERY VERY expensive. Suggest getting a new TV. The LC32D40U was a bad model.
Sounds like overheating. Is it physically mounted according to instructions so that it can "breathe"? Keever
I've repaired hundreds of tv's, but got out of that type of work before flat screens came along, so it will difficult for me to help you. But it does seem highly probable that something is overheating. Capacitors are infamous for "leaking" and thus running hot after having been on for a while. Many chips will also run hot after working properly for a few minutes.
Here's what I would do if I were you. Take the back off tv and replace it using only about 2 or 3 screws. Then turn it on and as soon as it shuts down, UNPLUG THE TV and quickly take the back off again and using one of your fingers, touch all the capacitors and chips one at a time to see if you can find the hot one. Polarized capacitors are the ones that run hot. These are round and will be taller than they are wide, sort of like a cattle grain storage bin. They will have two pins soldered into the board. Touch all the biggest ones first, then the medium sized, and so on. Then touch the biggest chips and the big transistors with three pins. The components mounted on metal "heat sinks" are supposed to run pretty warm, but nothing should be REAL hot, so if you find something really hot, then replace it. Do you have a service manual or schematic by any chance? Keever
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My 32D40U would turn on for 5-10 seconds (Please Wait would appear) and the screen would go black. Sound Normal. It would also sometimes do this after running 5-10 minutes. I read somewhere that the inverter board would come loose and lose proper ground. I took the set apart, removed the board, and cleaned up the grounding points. I reassembled using some copper paste on the ground points and LockTite on the screws. I used some contact cleaner on all the connectors going to the board. I noticed two cables that are covered with copper shield tape where too tight at their connectors and repositioned the tape to give them some slack. The problem hasn't occurred since the fix.
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Thanks for the suggestion keever, but the vents are clear and used vacuum to blow and suck any detrius from the interior... No Joy.
Just an update...
Called Sharp, then an authorized service center. Tech said it was the lamp behind the display, the replacement display was $1900.00 if available but it was not available...
Have a call into Sharp asking what they can do to assist, will relay final results on this forum.
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