How do you turn off picture in a picture

If the TV is still under warranty return it ASAP. The set will need to be serviced

Need to know if older set with picture tubes---turn color off--if yellow screen you have a loss of blue of some sort--red and green will give you a yellow screen. If set has the 3 picture tubes look inside in the lens to see if all 3 have a image---little or no blue means a problem there.

The first question is does the whole screen turn somewhat blue or just the sides of the picture?

If when it happens you turn color all the way off what does the screen look like? (black and white or blue etc)

If entire screen or even just the sides look blue first place is to with set off make sure all three of the boards (one at the bottom of each tube) have not come loose and come down just a little bit.

Let me know what you find and I will try to assist.

You have two problems: blue lines is convergence problem and the blue screen and shutdown is Blue Screen control is up too high.

You have a focus/screen control box Find it and adjust the R/G/B screen drives When you first start Go to Menu turn Color off then with a mirror adjust the picture as close as you can to a black and white picture R/G/B screen drives, the little control box you are looking for will have 3 controls on top for focus and 3 controls under them for screen drives to each tube red,green,blue after you have adjusted to a black and white picture then go back and turn color on.

id check the blue screen control first
its at the bottom of the set you will have to take the front panel off and behind it is another small black panel remove that one
and to select any function those controls need to be attached so slide that front panel to the left there and take you remote put the tv on video input
and there are sic controls on this little black screen control block
look for the screen controls and turn the blue one just slightly clockwise and you will see the blue screen will light up and you will have little arched lines turn the control back slowly till the lines disaper and the screen goes black

and then cycle the set off give it five mins or so and restart it and see if every thing returns and your video is being displayed then switch it back to your input and view and reassemble

I f these lines are slightly diagonal and they all showed up at the same time. you probaly have an open resistor in the ABL circuit. since your set is 13 yrs old, I would not put a penny into it.
You might take the front grill cover off and the panel behind it and find the little black box with 6 little controls 3 are for focus 3 are for screen turn the screen ones ever so slightly counter clock wise. the control in the middle is the green screen adjustment. If the green line goes away try the one labeled r for red and b for blue.

The black box is caused by the Closed Caption option of the tv. Go into the menu and turn it off.

It sounds like the Blue drive transistor is shorted out leaving the blue color gun on full blast which is drowning out the other colors. If this is the case the transistor needs to be replaced. A qualified technitian could easily replace this part.

I have the same set. I solved this by turning off the dynamic contrast or adjusting the contrast and brightness settings down.