No picture I have a Westinghouse LCD television when I cut it on the picture appears for a second then vanishes. What could be wrong?

The 1 or 2 long LCD inverter boards are dead.These boards,the 1 or 2 long LCD inverter boards are not giving the LCD screen a backlight any more,that why,u only have a flicker of a picture for a few sec only.Have only sound left.Tries websites like Shopjimmy.com,Ebay.com to buy those refurbishes 1 or 2 long LCD inverter boards for the replacement.

It is either the 24vdc power supply is not working or the backlight inverter may have shorted circuits, those are the two areas you need to check.
If you are going to DIY and have proper tools, electronics knowledge, and know safety precaution then please read on:

Please see my basic troubleshooting guide here:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide

http://s807.photobucket.com/home/budm/allalbums

http://en.wikipedia.org/wiki/Capacitor_plague

Parts: www.shopjimmy.com

Please post back what you find.