I have a Samsung 3D plasma PN51F8500AFXZA with a similar issue, black blotchy spots on the screen at start up then it diminishes to leave black pixelation all over the screen like fuzz or static similar to the above issue. Ive checked for shorted mosfets and caps on the y sustain brd and found none. Moved to checking voltages on the X sustain brd and found some voltages that meta ai says are abnormal. On the x sustain i found the VE as 100 vdc, the SVT_OUT as 75 to 85 vdc fluctuating. On the ribbon connector going to the Y sustain the XERC as 120 vdc. Meta AI says those voltages are not correct...

New member, i enjoy repairing all things. Ive hit a wall working on a samsung 3d plasma tv pn51f8500AFXZA i have basic knowledge and tools for electronic repair and have worked in the field in the past with community college courses. Id rather learn to fix the specific boards rather than buy replacements willy nilly.