Here is the Fix
I had the problem on a 55" LN55C630. Researching online I found that if the capacitors are good, the EASY fix involves cutting a jumper on the power supply motherboard. For my model this was jumper JP854. For model LN46C630 the jumper is JP852.
Steps to repair:
1. Remove back panel - 18 screws
2. Find the jumper on the power supply board (which is the one the power plugs into) on the upper left. DON'T TOUCH THE BOARD IN 'HOT' REGION.
3. With wire cutters, cut the jumper wire on the motherboard, so that they no longer connect.