i was trying to get an owners manual for a 2nd hand jvc kd-g720 car stereo to try to get the clock set. i did it once by pressing and holding the sel button to put it in that mode but this time it will only display demo on or off. what am i doing wrong? also does this radio display the artist and song playing and how do i turn that on if it does? the guy i bought it from said it did.