My father convinced me to just buy a cheap lcd monitor to use while my computer’s screen is broken, and to wait a year or two or however long it takes to get a new computer. I think it is good advice. I’ve found some with monitors that can sort of be placed above the laptop’s screen. And they’re cheap.
My father also identified another area which could be causing the problem: when you close the laptop, the screen trips a switch of some kind to shut the screen off. Perhaps that switch is stuck between on and off, causing it to turn on and off. If so, rapidly opening and shutting the lid might shake it into place. I will suggest this to the repair place.
Meanwhile, I am looking at the Samsung 740BX as the cheap monitor. I finally determined that the newer 743BX simply added dynamic contrast — an annoying technique of dimming the screen during dark scenes to create the illusion of deeper blacks. This does not fool me. So, the 740BX.
Update: I may actually first try taking my laptop screen bezel off and seeing if I can identify the inverter part number (there are 3 potential versions on this model). Then I’ll buy an inverter at cost, and replace it myself to see if that fixes it or makes no difference. The inverters cost about $50 or $60. I don’t need to pay the repair place to do this, it looks easy. And then, if it does not fix it, then I’ll get the external monitor — an open box item, not new. (I also considered finding my same laptop on ebay and using it for parts). If I get the external monitor I may end up removing the external monitor’s base (or just not attaching it, seeing as they usually come unattached) and somehow clamp it in front of the broken laptop screen. Maybe with actual clamps from Home Depot. It won’t be pretty, but it may look kinda neat. Albeit unportable. So right now I am just waiting to drive home, pick up my flickering laptop, get a tiny screwdriver out and see about removing the bezel of the laptop screen. The screws are reportedly hidden. I’ll find them. You know you’re into computers if you have one of those little screwdrivers, especially if it has a magnetic tip.