I have a 3 years old Toshiba Satellite L750D. A couple of days ago it's screen started having random noisy horizontal bars on the screen (some noises for 1-2 seconds, then nothing for minutes, then noises again). After I rebooted, the screen backlight died completely. So I called a service where I got informed that LED screens don't have inverters or any other source of backlight problems, other than the backlight itself going out, and that backlight can't be replaced separate from the screen, so I would have to buy a new screen. Last week I went to the service, bought one and had them install it.
Ever since then, when I move the lid at around 90 degrees, or lift the laptop with the lid open at that position, I often (not always) get this annoying flickering (whole screen going black for a split second, sometimes 2-3 times in a row). For first I suspected cable malfunction, but I could also hear a strange, soft electric noise during these blackouts.
Yesterday I took it back to the service. Cables were OK, after a quick look they didn't know what the problem was. It seemed to them like something with the lid switch was going on which clearly wasn't, given that it's a magnetic sensor near the touchpad and has no interaction with the open lid. And now a couple of minutes ago, when I disconnected the charger cable, it went off (with noise) for like 2 seconds, then back on again, so I'm afraid it might even be a motherboard issue.
Any information/help would be appreciated.