The handheld remote control (in the late 2010/early 2011 shipments of DCS Systems with Rev. L TIU) has limited contrast. The fix involves moving the resistor from pin 7 to pin 6 on the leg of IC U161.  After moving the resistor to the correct position the LCD now appears to have its normal range of contrast. You will need a very small tip soldering iron, a magnifier, nerves of steel, and some luck to pull this off. I repaired mine but wouldn’t want to do it repeatedly without better tools. The photo shows the correct location of the resistor.