Check the status.
The LCD displays built into all Sony portable systems are produced by the highly accurate technology. However, no manufacturing process is perfect. On an average LCD display, there are some 2.36 million individual transistors printed onto the disply panel, and it is not uncommon for 1 or more of these Picture Elements, or pixels, to be stuck in an unchanging state.
The visible result is a black spot (where the pixel is stuck off), or a constant Red, Green, or Blue spot (where the pixel is stuck on). In most cases, these stuck pixels are hard to notice and do not detract from the display quality or usability. an important point to remember about stuck pixels is that they are fixed features of the display and will not spread to nearby pixels.
We would appreciate it if you understand that this is within the specification as long as missing pixels do not affect the operation. The following note can be found in the Instruction Manual:
"The LCD displays are produced by the highly accurate technology, however, black pixels may be found, or red, blue and green pixels may not disappear. These pixels shall not be regarded as a failure."