Today I noticed a green color in the top, right corner of my TV screen. It's on every channel so it must be the TV. The TV is 1 1/2 years old. It's a Sanyo 27" 480i - model # HT27547. Any ideas as to what this problem is?

Possible magnetic interference. Have you recently located an electronic component or speaker near(er) that side of the set?

My mother put her boombox on top of the TV when the TV was off. I can't remember if I removed the boombox before or after the TV was turned on. Don't know if that matters. The boombox was sitting there for 1-3 hours. But if it was the boombox, there would be two green spots, right? I think there might have been, I'll have to check. Can this green spot be fixed easily?

Your set needs to be de-gaused, any TV shop can do this.

The TV should fix itself, the hum you hear at power up is the degauss. After a few times powering up cold, the green should clear up.

The green spot seems to be gone now. I'm keeping an eye on it though. I hope it was just from the boombox and not some bigger problem.