DIAGNOSIS This is a known weak point. The LCD ribbon cable connector can become loose or the cable itself can fatigue from case flex. It is a physical connection issue between the main board and the display assembly.
FIX Firmly press on the plastic casing directly around the LCD screen. Apply pressure near the edges. Sometimes this reseats the internal connection temporarily. For a permanent fix, the unit must be opened and the ribbon cable re-seated or replaced.
IF THAT DIDN'T WORK The backlight LED driver on the main PCB could be failing. If the screen information is visible under bright light but dim, the LCD is okay—the backlight circuit is not. This requires component-level repair.
HEADS UP Opening the unit voids the warranty and exposes high-voltage capacitors. Do not attempt internal repair unless you are qualified. The display issue does not usually affect charging or output function.