Internal display problems after repair

Dirt in the female-side is a possibility. It was quite dirty in the case and I blew it around.

I certainly did disconnect power before anything else.

I’m not sure what a test screen is. It sounds like you are eluding to a troubleshooting process I am unaware of. If its simply a test pattern, i don’t see what it’ll tell me. If it was a logic board problem, then external displays would also fail, no?

Test screen as in try a known working screen, to see if it resolves the issue. It could be a logic board related issue affecting only the internal display (GPU issues only affect both the display and outputting to another display).

Try a known working screen, but first clean the LCD connector; otherwise you are just guessing.

Trying another screen is a rather obvious step. I would if I had any lying around. I'm just a dad with kid who's Mac I broke. I've tried brushing and 91% alcohol. Neither made a difference. I've finally ordered a screen. Thanks for the feedback.

I know, but it is necessary when diagnosing an issue; exhausting all easy solutions before looking into the more complex issues. Otherwise you are just trying to find an issue with a part which may be working absolutely fine. Picture issues like this are always related to the LCD from what I have come across

Problem follows computer; Test screen shows same pattern. Tried cleaning female connector again with 91% isopropyl alcohol . No change. Will disassemble main board again and check back side and other connectors . Don’t know what else to do. Perhaps I’ll disconnect anything non-essential (track pad, speakers, io, camera, etc.) and just boot with display ssd and keyboard, then try with just io and screen...