I have never seen an issue such as this one. horizontal lines across the monitor in a consistent manner. I am really interested to get to the bottom of this and I'd value any input from the community.
There are three separate PCB parts attached to each other. They function as SMPS, backlight driver and main board.
I checked the all three blue PCBs: SMPS outputs 19V, PWM controller + mosfets without anomalies, main board has 3V, 5V, 10.5V and 19V present. Crystals output the right clockspeed. This is to be expected as the monitor turns on.
I haven't explored at the green PCB (TCON...