Sounds like you have the Sammy HP-T5604 plasma? If so, its specs say its got a D-sub PC input. You may want to consult that book that came along with it. It's called an "owners manual".....sometimes there is valuable information in there!

I know, I know, if you cant find it on You Tube, you dont need it.....
See if this picture link works. Its the input panel on the other possible Sammy, the PN50A450P1DXZA
http://www.circuitcity.com/IMAGE/pro...N50A450.CB.JPG
At the top, is the PC input.
Losi 8T 1.0, Savage Flux - XL style, LST XXL, Muggy, 3.3 E-Revo Conversion and sitting outside 425hp, 831 Tq Dodge Ram Turbo Diesel. It SMOKES