Tv lg ultra slim no display but sound ok why?

Check the output voltage from its SMPS power supply. You should have some experience in service work to proceed. It it seems OK, then check the main board [horizontal output section circuit] and pin-cushion circuit for defective component/s. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
You can get an idea about the fault to an extent.
View the site by desktop or web view on mobile devices to see the "search box". Type in the brand name of your set in search box; to get gathered the related posts.

If you wish to get some details; visit the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
Type in the key phrase " my service table today " in the search box at the top right of the display window; and check the gathered posts. One among it will give you details, I'm sure.

Check and replace damaged component/s at its horizontal scan output section circuit. Check the LOT (Line Output Transformer) too for damage. Replace the horizontal scan output transistor. Check the input voltage to LOT. If the voltage is absent check the feeder resistor; if any. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/
Type in the brand name of your device, in the search box [at the top right] of the display window and the Search will start at once as you type in, and will show you all the related posts. It will make surf easy.

show me the picture than i can tell you the exact problem and its solution

www.lg.com/us/support

ok ur tv powersupply is ok but horizantal is not working chk ur fbt hot & micronass

pl chk horizantel driver is not ok

Change display settings to Wide 16x9

thanks very much about your technical support.but i solve allready the problem of LG LCD TV MODEL LT-15A10 TROUBLE; no picture with sound, i replace the socketed ic SDA555XFL62 PINS. THANKS... LODIVAR.