Entry LCD lighting/lights-outs mode (Press No. 3 button)
This diagnostic screen checks for segments that may be dead (off) or stuck on.
All the segments in the display must appear. If there are dead segments, replace the center panel (see step 9 ).
When the display segments are all on, press the No. 3 button. The entire display must turn black. If any segments are stuck on, replace the center panel (see step 9 ).