What would cause a flat screen tv to have sound but no picture

Back - light problem. Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis.
http://electro-medical.blogspot.com/
http://electronicshelponline.blogspot.com/
To some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement. To some models sets, the back-light inverter and SMPS section circuit will be integrated at its main board itself. If so; the main board should be replaced. To some models of sets, all these section circuit will be integrated at its main board. If this is the case, you have to replace the main board.

Back - light problem. Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis.
http://electro-medical.blogspot.com/
http://electronicshelponline.blogspot.com/
To some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement. To some models sets, the back-light inverter and SMPS section circuit will be integrated at its main board itself. If so; the main board should be replaced.

The T con board is faulty. It is the board with flat ribbon cables going to the bottom of the screen. It is not hard to replace this board. You can get one from here:
TV Parts Universal TV Stands DLP Chips ShopJimmy

Replace video board. That fixed mine and not hard to replace.ordered mine on e bay. Lay TV flat on something soft so not to scratch screen and remove back. A few screws and a few plug ins. Remove old card install new one. Pretty much plug and play.reinstall back cover. Done.took me about 30 minutes.

Sounds like your screen has given it up.
Suggest buy a new tv.

put a flashlight behind the TV screen or front screen close, just try as close as possible, if you see image that means that the Back-Light inverte is defective or the screen lamps are not working, if deres no imagen the video card is not working (main board)

I just repaired this LCD tv exact same model.
symptoms- when the tv turns on, all I get is a black screen with blinking green light. No other error codes. It was crazy frustrating trouble shooting this. I measured the transformers on the master and slave inverter board with a multi meter. The resistance should be 1.31 k ohms. All but one measured within the specs except one. I get an OL reading. I took a chance to order this part on eBay for 13 dollars. After soldering it, the resistance for all of the transformers were back to specs. The tv powered on and stayed on. Works good as new. If anyone has the this similar issue I would advice testing the mini transformers on your master and slave inverter board. My email is [email protected] for help.

lcc5255u aquos fixed
lcc5255u aquos resolved

In what way is the screen broken? cracked, distorted picture, no picture but has sound?

If it is cracked. Replacement of screen is expensive. Cheaper to buy a new TV.
If Distorted. Parts linked to the screen can be the culprit. Most common part to fail is the T-con board. Main board may not be sending signal to the T-con board.
If its no picture but has sound. Back lighting has failed which could be several things that can cause that.

without any other details besides "broken" it will be hard for someone to help with diagnosing your problem. We need symptoms like. has sound but no picture. Picture has horizontal or vertical lines. part or half of the screen is black, black borders don't count. Hope the info here has, in some way, helped bring you closer to what to do with your TV.

HelloCheck the backlight inverter board. If it has damged, most common fault to LCD TVs, there will be no backlight to the LCD screen, and will look black. Your tV has sound output without picture. This means that all other boards ar functioning well. Check the backlight inverter section and CCFL tubes used in backlight assembly. OK.

Do you know if i can use an inverter from any LCD tv, or does it have to be specific to that model? I was thinking about taking an inverter from another broken TV.