I replaced the color wheele in my Samsung HLN617W

When you replaced the color wheel it sounds like you took the DMD board out or you bumped it? Either way the DMD board will need to be realigned and that involves reaching into the TV while it is in normal operation. The DMD board in the one sitting right behind the digital bard and has a small fan facing the heat sink on it. There are three screws 2 on the left side on one on the lower right that need to be loosened just a bit and then with the set on you will have to move the board back and forth to achieve dead center. Remember from the back moving the board to the left moves the picture to the right and pushing down on that board will shift the picture upwards.