Problem with ps2 plz help

[thegoldbergfan]

i would like to tell u my problem so maybe u know how to fix it.
i left my ps2 vertically for monthes. and then when i pressed the reset button(when its red) to turn it on i hear a sound like if the ps2 can't boot itself (the problem is from the cd drive i think) then the blue light(on the eject) comes on. and every day the sound becomes longer.
but in the end it made the sound for 4secs then the blue lightning comes on and i fi pu I any cd or dvd it does nothing for few secs then it becomes to make a sound like if its unreadable and doesn't give me any error it continues to display reading disc...
but my ps2 is modded (messiah 2).
but the strange in this problem is if i hold my ps2 in the air and hit it 2 or 3 times it works.
but when its working if i put a cd that i have copied or any dvd, and when it can't read it(when i'm in gameplay it can't read music...) it makes a sound (an ordinary sound when a disc is scratched) and i turn the power off or i eject the disc the problem recomes so i have to rehit it.
can you help me??? plz