NEED BOLT SIZE TO MOUNT 42 JVC LCD 120HZ PLEASE

2/3 12"

try your local hardware store, use a pencil as a guide to help size the bolt needed, you might need to buy a few different sizes, but make sure it's the right tread ! you can return the bolts not used, you need 4 bolts total and there mostly metric.and a certain length DO not use long bolts !
If hanging the mount on the wall, once again ask your local hardware store guy for assistance, these tv's are heavy and need to be mounted properly, and can kill if they fall. so do it right !

Back-light fault. 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. Viewing it in "Mosaic" or "Magazine" will make surf easy. Surf the site with patience. Pull up older posts. Do a search by type in the brand name of your device at its search box. It will be best to replace the inverter board as card basis.
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Contact the authorized service center for Vizio.

If its still under guaranty take it back.
Sorry couldnt be of more help.

It is very likely that the correct mounting bolts to attach a wall mount to your TV are type M8 bolts 20 MM long. It is a rather standard size and you should be able to find them locally without a problem. This is the most probable size although you may find that it requires a different size. It should be either a M5 or M4 bolt of similar length. Give it a try, I think you will find it works perfectly!

They are Metric screws, either M5 or M6, you can get them from hardware store for about 25 cents each, so get different length depend on the mounting brackets.
Wall mount usually comes with mounting screws already.
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The bolt size you need is: M8-1.25 X 20.  20 is the length that I used and it works well.  You could also use 25 (which is a little longer) if you would like.

 

It took about 5 trips to Home Depot and Lowe's and a few hours searching the web before we got it right.