Samsung S5033 plasma problem switching off&on

[bailey11]

Model: HP-S5033, Model Code: HPS5033X/XAA, Type: CD50P7
Initial problem: loss picture sound was ok.
I found a 6.3A fuse blown (F5002) on the 50'HD W1 Y-MAIN (Model No on board, not sure if that is really a hyphen) PCB Code: LJ41-04516A.
I replaced the fuse.
Now the Stand-by turns on and off. (relay pulls in then releases)
All caps look good.
The power supply board is a Model PSPF501A01A.
I disconnected a harness that goes to another board which connects to the X-Main & Y-Main. PSB relay continues to cycle on & off.
There's another board behind the board where all the Ant. cable, HDMI, component cables connect (Model Porsche/Cadillac, that's what it says) that is connected to the PSU board with led that flash on and off with the relay cycle.
When I disconnect this board from the PSU, I hear the relay click only once and the led on the power button, on the front of the tv, flashes 4 times and goes out. Note: this other board also connects to the X-Main & Y-Main boards through ribbon cables (not sure how to disconnect these).

I sure hope someone can help me out here.

Steve