My ps2 won't work, but i have all the cords plugged in?

May be...

it just shows this blank black screen....HELP.

have tried changing the channel to L2

if it doesnt work take to the nearest game store to fix.

but can you hear sound???? cuz if you can then you just have to wiggle around the cord with the red, white, and yellow cords until you can see the screen I had the same problem