I own the CDT-10. I just read through the online manual, but found no mention of how to dim the display. My <hazy> memory tells me there is a way to dim the display. Has your friend tried the display button on the remote? [I don't recall what options are available once this button is pressed.] Thanks to the holidays and my adorable 5-month old grandson, I'm unable to access my remote to try to dim the display.
Michael