Television and Home Theater

I have a sony KP51WS510 i removed all connections on the D-board but i can not after numerous tries remove the larger red high voltage cable that connects in the Flyback transformer. THis transfromer has two cable one large one small, the small one i read on other post that comes pull out to a bare end, the larger one is to be twisted 90 degress and it will pop out according to service manual, but it does not. i have twisted it clock wise and counter and nothing. My hands are killing me, this is all i need to remove the d-board. please help.

Hello everyone.  I am new to this forum, and would like help trouble shooting a picture problem.  I have a two inch green shadow on the right side of all images.  I have tried using the convergence to correct the image problem, but my problem is this the red convergence moves both vertically and horizontally, while the blue cone will move up and down, but not left and right. 

I get power to come on for 10 seconds and a blue screen comes on. It then flickers and goes off