It's not a notebook. It's an All-in-One. There are flickering horizontal lines on the display, sometimes better, sometimes worse. We checked for, but did not find any new interference source and it was perfect yesterday. It is a new machine.

try changing picture size

flickering as the picture becomes smaller and bigger or are there lines showing up? Please describe it better if you can so I know exactly what you are seeing. Any color changes?

separate wiring. touching wires creates cross-talk of signals.

Probably the problem comes up with two different reasons. 1st is Horizontal control section in LCD may failed or in irrecoverable situation. 2nd is display drivers crashed or not supporting the laptop.

Power supply is probably going out. Not likely the video card in this case.

Either bad capcitors, or (if you're lucky) the color wheel needs lubed up. Probably bad caps.

It appears the video cable connector needs to be seated properly, it may be loose. The connector would be located near to bottom of the screen on the motherboard between the hinge and the top edge of the keyboard.
Depending upon the model of the laptop there is a plastic panel which houses push buttons and indicator lights that is located between the top edge of the keyboard and the bottom of the LCD screen. There are screws at the bottom of the laptop and possible screws on the back next to the hinge securing this panel. This panel would also have small plastic retaining clips locking it into place. You need a thin blade to lift this panel up, be careful not to crack the panel.
Once you remove this panel you see this video connector and cable. the connector may also be held in place with a screw and plate.

i would like to see the pictures
thanks

this is real old right
no photo off i messing up, how can we guess, what you see?
amazing....
my guess power pack shot.
i guess you cant barrow a monitor and try that?
2nd guess blind, the back light failing
or is damage if it was hit, the LCD will have damage
gently flex the frame goes nuts, bingo.

Try reloading the drivers, delete the device in device manager and reboot. It should then pick up the drivers and reload them, if that does not work I would suspect the screen is on its way out (flickering normally means the screen or its connection is bad)