Screen fades to blue.
The Blue SCREEN setting is too high. These adjustments are located inside the TV behind the front panel. There are two screws behind covers and then a wooden panel to remove to access the adjustments. The leftmost set are for BLUE, the middle are GREEN, and the right are RED. The top row are FOCUS and the bottom are SCREEN. Focus will focus/unfocus the tube and Screen will adjust the power of that tube (there are 3 tubes, one for each color). If Screen is adjusted too high, horizontal lines will appear (my TV had red lines, but I played around with the knobs and saw that it could happen on any of the colors). Additionally, if SCREEN is set even higher than that, the tube could go so high that it turns the whole screen that color (in your case, blue). If this happens the TV will shut down, probably due to either overheating or overvolting. To fix this issue, turn the appropriate SCREEN dial down until the lines go away. In your case, you want to turn the lower left dial down. Don't turn it too far down, if you turn it more than necessary the TV can give you an AKB error (noted by the STANDBY light flashing a sequence of 5 blinks).