Horizontal and vertical lines on MacBook 16’ computer.. help?

To rule out any potential damage, per chance did your notebook experience any type of liquid spill recently?

If so, I recommend that you stop using it immediately and be sure to power it down completely. Then make a Genius Bar appointment at your local Apple Store or Apple Authorized Service Provider to have them take a look and provide you with your options. Any further use, in this case, could potentially cause more damage.

If not, then, give the following a try to see if they can help:

1. Boot up your notebook in Safe Mode to see if this issue continues. Ref: Use safe mode to isolate issues with your Mac - Apple Support
2. Reset your notebook's SMC. Ref: How to reset the SMC on your Mac - Apple Support
3. Run an Apple Diagnostics test: Ref: How to use Apple Diagnostics on your Mac - Apple Support

Please post back your results.

Hi,

First you need to be sure that there are no cracks on the display. That kind of line pattern are a typicall symptom of accidental damage, check for small cracks near the lowest edges of the screen.

If the screen is OK connect the MBP to an external display to see if the line pattern replicates also there, if the image shown in the external display has no lines then you have an issue with the Display (most probable) or the Main Logic Board (less probable).

You need to take the MacBook directly to Apple or an AASP for the repair, they need to run specific post-repair test to calibrate the new display and LAS (Lid Angle Sensor).

There are no 16 foot MacBooks.

Find an Apple Authorized Service Provider nearest your location. Just fill in the Country and City information. As for costs - only they can answer that question