Intermittent display issue

[pkapelanski]

I'm having an intermittent display issue with my HP Omen laptop, model X7N74AV, purchased about 3 years ago. The issues started about 3 weeks ago. As far as I can tell, there wasn't an event (like a drop or spill) that caused it - my laptop has been in daily used but hasn't moved from my desk in months.

Initially, I would get shifting, multi-colored, streaky patterns displayed on the screen (see photo 1 below). Sometimes the streaky pattern would display for a while, then the display would start working normally of its own accord. Sometimes, adjusting the angle of display forward or backward would cause it to start working, or cause it to go streaky if it was already working. This was getting more frequent over time.

The display itself is the only issue. When it's working, and I'm able to use Windows, everything works normally. I tested with an external monitor connected to the HDMI out, and that works normally always (even when the built-in display is acting up). I updated the graphics drivers and BIOS, which produced no change (for better or worse).

Based on these symptoms, I ordered and installed a replacement display cable. This has changed the symptoms, but not eliminated them. Now, instead of rainbow streaks, I get a gray pattern (see photo 2 below). Sometimes, for no reason I have identified, it starts working normally. It seems to be all or nothing - either gray pattern, or displaying perfectly with no issues. This has become very frequent - now it's stuck like this most of the time, and working only rarely. Changing the angle of the display doesn't seem to have any effect now.

My question is - what should I try next? When it's working, the laptop still suits my needs, so I'd prefer to fix it than give up on it.