I have a slim xbox 360 with a iffy hdmi port, it has hundreds of moving red speckles on the screen and black lines flashing on it, if you move the hdmi cable around, and hold it manually to one side it clears it up.
Ive tried scraping the pins lightly with some cleaning tools (no liquids etc)
but still no dice.
Is there a way to fix this? no chance of warranty its been modded