Screen has washed out blurred lines for a few minutes

Hello all .... thanks for always helping out. I have a Macbook 3.1 core 2 duo with a 2.2 GHZ processor. Sometimes when I start it up, the screen has few washed out vertical lines from top to bottom: colors go between Pinkish an green. You cannot make out anything on the screen for about 5 minutes. This goes on for a few minutes and then everything is back to normal. I know the computer has booted during this time because the screen brightness buttons and volume buttons work. Then after it has started working, yo can restart the computer without any issues. Please help. Do you think it is the inverter?

The last 3 characters of my serial number are Z63. This morning, I closed up the computer and fixed the keyboard and stuff back and it did the same thing. I had the laptop on the table as i was putting all the screws in and so when I turned it over and started it up: same fuzzy lines. Withing 2 mins, I picked up the laptop to put it into a better location and the screen suddenly worked ok. I have tried pushing the back of the screen to see if the screen does anything, but nothing happens. I tried tapping the bottom cover but nothing again. Works fine. Beats me .......

Zahan