If the screen shows lines, dots or random characters then the fault may be either caused by a faulty screen, motherboard fault or defective cable where it passes through the laptop hinge.
A very dark screen (ghost image) can be caused by a faulty screen, but is more likely to be caused by the back light not illuminating. Back light illumination is very complex, faults usually occur due to either a broken back light lamp, failed high voltage inverter, broken cable, faulty motherboard or faulty switch.
So what looks at first sight like a screen fault may not be but caused by another component, screen replacement is expensive £100 - £500 but other causes are considerably cheaper at £40 - £300.
Screen replacement is NOT a DIY job, as pressure in the wrong place during installation will crack the screen; and wrong diagnosis of the cause of the fault will result in the wrong item being replaced.
Trilogic can repair any of the faults listed above including those caused by motherboard failure.