My tv does not work on Youtube what can i do ?

Without being there and doing the diagnostic work I can't say.

If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
Line faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.

If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
Line faults & possible causes to LCD & Plasma screen are given with illustrations. You can get an idea about the fault to an extent. Faults to all LCD & Plasma screen are similar, irrespective of its brand and screen size.
Search the site by type in the "BRAND NAME" of your device; (Exclude the model number), in the "Search box at the top right of the display window of the Homepage" to get gathered related posts

LG plasma vertical line repair - YouTube

? 2:33
https://www.youtube.com/watch?v=24FkcQoeGPg
Feb 10, 2013 - Uploaded by Matt Mayer
I have an LG plasma, my vertical line is in the middle, as if one would have ... Panasonic Plasma TV TC-P50X5 Vertical GreenBar Line Fix ...

EASY HOW TO FIX LG plasma TV - color bars - YouTube

? 4:45
https://www.youtube.com/watch?v=QyaBiSkc1l8
Dec 16, 2010 - Uploaded by Tampatec
diy HDTV Plasma tv repair tv reparar the red green blue color stripe line vertical bars T- control t-con ..

Fault to the main power supply regulator section. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electro-medical.blogspot.com/
http://electronicshelponline.blogspot.com/
It will be best to replace the power supply regulator board as card basis rather than making "Surgery" to it; which usually will make loss for both money and time. Even though you can make it right, it will cost around an amount equal to the cost of a new board; including the cost of (spare parts + service charge) More to say, most of the spare parts to it will be difficult to get from open electronic spare part market. This is true to most of the flat panel TV power supply boards; irrespective of its brand and screen size.

Probably the hdmi switching is is faulty. Its there in the mother boar of the tv and also it will be an smd ic. If the port was faulty you should get video in any one of the hd mi port.
www.electro-medical.blogspot.com

Fault to its main board. Short circuited component/s at it. Contact any service technician; or the authorized service center. 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/ . In most cases, the main board might have to be replaced. If so, a software [firmware] update too might be necessary.

It is shutting down because of a fault,which can be on any of the boards it needs to go to an engineer for repair.

At this point my best guess is that you have a bad main board that's all I can tell you from the information you've given

Check its audio output card for the fault. Click here to get more details.