If Its Not The Bulb

So the problem is obviously in the optical engine. So if you are wanting to troubleshoot this yourself then get the set into a serviceable position. place the TV on a table with the back facing you, take the bottom back cover off and you will see the interlock switch next to where the lamp door was. Pull the wires to the switch up and over the lever to hold it in the back position (towards the front of the TV). then have the AC cord ready with a good flashlight and a small dental mirror (or something equivalent). you will see the "signal section" on your left and the optical engine on the right with a thick cable connecting the two together this is the cable that communicates between the DMD board (the board clad in a big metal shield and a fan is pointing at it) and the microprocessor (in the signal section). This DMD board is the brains of the engine, and I have see this cable cause your problem, so disconnect both end and reconnect it to see if the problem goes away.

 As described in the previous question before the lamp gets the high voltage from the ballast circuit the color wheel must get up to the proper speed. so plug in the TV AC cord and when you turn the TV on you should see the cooling fans start up, a couple seconds you should hear the color wheel spin up. the color wheel is physically right in front of the lamp inside the optical engine. If you cannot hear the color wheel ten it could be frozen completely. Normally before this happens the color wheel motor bearing would squeel like a bad fan, or if the color segments have fallen off then it would vibrate very loudly. The color wheel price $105: http://www.encompassparts.com/item/6729532/Samsung/BP96-01579A/Assy_Color_Wheel_P. You can also take the lamp cartridge out of the engine and with the flashlight and mirror, peer into the engine through the hole the lamp shines into and plug in the set and watch for the color wheel to spin.(how to change the color wheel: http://www.youtube.com/watch?v=Cx4pbNjsxfU ).

If the color wheel is spinning and it sounds like it is speed is stable then the DMD board will tell the ballast (http://www.encompassparts.com/item/7120742/Samsung/BP47-00037A/Lamp-ballast) to light up the lamp. Although without a volt meter you cannot test this section. It has nearly 400 VDC going into it and it makes 5,000 Volts to the lamp, so keep your hands away from this when turned on. I have seen many of these fail when a lamp explodes.

finally, the DMD board (http://www.encompassparts.com/item/8353803/Encompass_Certified_Part/BP94-02269A/Assy_Pcb_S-dmd) has been a problem for these sets from time to time, and it is almost impossible to check. It usually becomes clear that this board is the fault only after all other parts have been changed and checked.