How do i fix only sound and a blue screen

Try resecuring the ribbon cable. make sure that none of the metal contacts on the cable is bent or broken.

get a new main board

The main board needs replacement very common issue. You can get a replacement main board from www.tvrepairworld.com

Hello,

Problem is in either power supply or the Y-Sustain board.

The Y-Sustain is a relatively large board out of which go connections to the side of the display; it's therefore closer to either the left or the right side of the display, has at least one rather large heat sink on it and fat power cables connecting it to the main power supply.

Often there are fuses on that board - one or more. Check those.

if they are blown you can try to replace them, but expect them to blow again - usually the whole board needs to be replaced.

I hope this will help to solve the problem....

Good day!!!

If the output voltage of the power supply is complete and no voltage drop....

It means the main board/system board is not function/initialized...In that case the processor i.c is defective but the i.c is very sensitive and difficult to replace so its not for D.I.Y...

In that case the only way to fix it is to buy/order a new system/main board that compatible to your brand and model..

SIMPLE BUT HARD SOLUTION, TO CORRECT THIS PROBLEM YOU WOULD NEED TO REPLACE THE MAIN BOARD. SIMPLE. I DONT KNOW WHO ACTUALLY CARRY PARTS FOR THESE BECAUSE ITS A BEST BUY BRAND, HARD PART.

MAIN BOARD IS A SURE FIX IF YOU CN FIND IT

yes go to www.shopjimmy.com get the main board of your tv and replace it lcds usually have 2 power supply and the main one thats the problem tv repair man told me it incharged of all your inputs sound and picture but he was charging too much and the manufacturer too 149.00 shop jimmy 108 with shipping glad too help you and you r welcome and it aint no science to do it your self do it on top of your bed thats how i did mines in order to get the model number have to be real careful with the screen oh and you r welcome

Yes,Ur Main Tuner signal board is dead.Replaced this Tuner signal board will solved this problems.Tries these websites Shopjimmy.com,Ebay.com to buy a refurbish Main Tuner Siginal board for the replacement.

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://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.