1) Partially light, partly dark
This situation is likely to be due to the use or installation of accidentally scratched the light guide plate, because the light guide plate is mostly using acrylic material, acrylic material has the characteristics of high light transmission, but the disadvantage is very fragile, such as by external forces scratched easy to crack, resulting in partial darkening. The only way to handle is to replace the light guide.
2) Partly bright, partly unlit
This situation is caused by the problem of ultra-thin light box light source, because the light source is LED patch lamp beads, a few light beads do not light and do not affect the use, but most of the lamp beads do not light will appear such a problem, to deal with this situation simply need to replace LED patch can be.