Horizontal lines across the top 2 - 3" of the screen

Sound like your Y-Sustain board has one foot in the grave. The Y upper buffer and Y lower buffer boards go when the Y Sus Goes too...

Without seeing the lines I can't be sure what your set has wrong, but here are a some possibilities:

If the lines are lines are confined to the top inch or two of the screen and the picture looks otherwise normal, the trouble is bad capacitors in the vertical output circuit. Fixable by replacing the bad parts.

If diagonal lines are across the entire face of the picture tube and the picture looks washed out, the trouble is often a bad capacitor on the 200-volt line to the picture tube. This may be on the main circuit board near the horizontal output transformer, or on the small circuit board plugged onto the end of the picture tube. Again, replacing the bad capacitor can fix this.

If your TV is actually an RCA, someone may have bumped a rear-panel adjustment. On the back of the TV near the bottom right are two small knobs. RCA left these adjustments exposed inside of putting them inside the set like other manufacturers. These sometimes get bumped if someone was behind the set cleaning, or if a pet got back there and hit them with a tail. The top knob adjusts focus, and the bottom knob adjusts something called G2 or screen voltage. If this gets turned up too high it can cause the faded picture and diagonal white lines. Turn the adjustment down until a black screen looks black instead of gray.

A bad picture tube or horizontal output transformer can also cause lines through the picture. If this is the case with your set, it's time for a new TV. The transformer is relatively inexpensive but labor costs aren't, and the repair bill may exceed $200. If the tube is bad, there's no point even considering repair. The tube cost alone exceeds the cost of new TV.

Hopefully your lines are easy and cheap to fix. Good luck, and thanks for using Fixya!

I would look for a Vertical circuit failure. Most likely is the vertical output IC and or open resistor off the hv transformer. Definitely look for any loose solder connections around the Vertical output IC.
Hope this helps,
Skyassoc

change the horizontal output transistor Big round quater sized thing on a heatsink. Next, posssibly the Capacitors are bad , will read 0 , big ones near the quarter sized transistor...

if this line is in the picture, that is possible burn in screen. if you have a black bar at the top or faint white lines that come down from top this is caused by defective filters in vertical circuit or bad vertical output. mch

Vertical hold circuit is failing.

Check capicitor in vertical hold circuit. You should have solid knowledge of electronics repair before attemping repair. TV's can emmit harmful radiation, and produce voltages up to or in excess of 30kV.

Hi I had the same problem. Broken white lines across the top of the screen. This is called overscan. You need to go into the Setup menu, other settings. 16:9 overscan needs to be on. Hope this helps.It solved our problem.

The complaint may be dry solderig or yoke ,horizontal or vertical oscilator

NOTE: ----DO NOT TOUCH THE CONVERGENCE BOARD " -------
1. Bring Up 1 Projector Light 2. Bring Your Color Convergence + Sign and Should Be Center In Your TV 3. If Not Adjust Center with The 2 Tabs Just Above That Projector Tube You Have Lighted 1 Tab Will Move + Sign Horizontal Then Roll The Other Vertical Then Roll..U Will See--" 4. Once Your + Sign Is Center Turn Up Your 2 Other Projectors Make Sure They Are Able To Adjust Across The + Sign You used 1st Make Sure the 2 Other + Signs Move Left And Right And Up And Below The Vertical and Horizontal Lines. If Not Adjust There Tab to Make This Possible. 5. Using Your REMOTE Converge The + Signs Together. ---------------- IF YOU MESSED WITH THE CONVERGENCE BOARD ------------------- 6. Now Lower The 2 Lights So Your 1st Projector Is Lighted 7. Bring Up A Menue On Your TV -- Look At It ...Are The Lettering Center and Square ..?? 8. If They are Lower That Projector and Light Your Projectors 1 At A Time To Verify Letters are Center and Square. ---------------If You Have To Adjust The Menue To Bring Center And Square -------- 9.Looking At The Convergence Board You Will See 3 Rows Of Adjustment Dials Each Row Is For 1 Projector. ---TAKE NOTE TURN THE ADJUSTMENT Slowly--- 10. Locate The Row that will adjust The Projector You Have LITGHTED".... 11. Label On A Paper What Each Knob Will Do To The Screen Very Help-Full 12.Adjust Your Letters Dead Center and Square then Lower That Projector Light And Bring Each Projector Lighted At 1 Time To Verify Menue Is Center And Square. 13.Leave On Your 3rd Projector and Bring Up Your Light On The 1st Projector 14. Adjust the Letters Of Your 1st Projector Over The Letter Of Your 3rd Projector 15. Switch To Your Convergence + Sign To Help --Turn Knobs Slowly --- 16. Make Your Letters Merge Together And Your Lines Square. 17. I Use The Top Letters and Lower Letters And Keep The box Square 18. Hey If Your Projector Colors When Looking Through The Rear Of The TV Are Not Equal With Take And loosen The Wing Nuts And Turn The Lens To Focus the Color and Make Narrow Or Wide....All 3 - Equal DO NOT GET UPSET THIS WILL TAKE TIME MAYBE ALL DAY SO RELAX HAVE FUN" Do Not go Sticking Your Hand Into The TV While TV Is Plugged into The Wall" ---

Clearly shows problem in deflection area both horizontal and vertical section. Horizontal lines is due to vertical section problem and making bbzzzz is due to horizontal output transistor short and sometimes LOT SHORT.