Screen freezes/flickers on startup, but self corrects after warming up

When I turn on my MacBook Pro, the screen freezes/flickers with what I’ve described as “melting” lines across it. It works fine when connected to external display, and resetting the SMC and PRAM didn’t help. I also tried replacing the LVDS cable with no improvement. The screen problem continues for maybe 10 minutes, and then the display is fine and works until I turn the computer off and try to use it again later. I’m thinking the laptop starts working properly once it’s warmed up a bit?

Is there a home fix for this problem? I really don’t want to spend the money on a new laptop when it works fine otherwise!