I have a toshiba big screen with three bulbs and the picture has wavey lines on the screen. Does this mean tubes are going out?

This set will blank the picture for several different reasons:

No filament voltage to the three tubes it uses.

No high voltage to the three tubes it uses.

No vertical or horizontal sweep (prevents all three tubes from having the screens burnt with a line.

Some of these can be tested but most require a schematic etc.

Set has several fuses and some do not look like fuses--called pico fuses.

Base from the description that you gave us this is really a symptoms of a bulb that is going bad and needs replacement already, because it will just go bad dark as time goes on so it will be better for you to have the bulb replace as of now ....

Good luck.........

57h84 IS A REAR PROJECTION SET WITH 3 picture tubes.

you got lines in picture top to bottom on the screen running left to right?

They go away after a while?

If you see separation of colors (red, green) in this wavey line most likely you have problem with convergence circuit. Two convergence amps have to be replaced. They located in a middle of the TV boards attached to big aluminum radiator and they part number starts with letters "STK".
I would recommend to let professional with this repair. Should cost you about $250-$300.
Regards.
Russ.

first is that tv have a tube if it does take back off and you will see what looks like a large light bulb tube and theres a clamp or two maybe even three clamps holding it inside the main big tube loosen the clamps being carefull not to get shocked by touching the wrong thing and the tube will slide back and forth it will also turn so place a mirror or just try looking around it when you adjust the tube to the correct messurement and make sure its level then lightly retighten screws be very carefull not to crack tube by over tightng hope this helped

That model Sony doesnt have a bulb it has three picture tubes cost about 250 -300 each and need to be properly aligned when replaced

sounds like the blue tube is gone out

wavey lines all over screen? does piture inmprove when it get warmer? this to me is indication of the "hypermodule signal processor" this can be fix but s a difficult repair. have to replace several VERY SMALL capacitors not a repair for novice.

Check the main filter cap and B+ line.

It is not a bulb. It is a picture tube. If there are thin blue lines across the entire screen, not just the edges, and the picture itself looks too blue, it means that the blue picture tube is being driven too hard. This could be because the blue screen voltage is too high, the boost voltage on the blue picture tube is too low, or the video output is leaky or shorted. If the picture has what looks like blue arcs and double images on one or more sides of the picture, it means that one of your convergence IC's has burned out and needs to be replaced. These are things that should be tested and serviced by a qualified tech, so allow an experienced tech to handle it for you.