Check that the cable from your antenna is connected properly. Check that your hard disk drive has sufficient space for additional recordings. To free-up space, delete some old recordings that you have already viewed. The DVR+ should tell you if your scheduled recordings were skipped or failed. To see the recording status for a recording that was missed or to see the status of another program scheduled to record in the future, press the Menu button on your remote. Now select DVR>Schedule. Please check the scheduled recording and make changes if necessary.
Did the box have power when the program was scheduled to be transmitted? The DVR+ (CM-7500) will wake from standby to record a program but it must have AC power connected to be able to do this.
One reason for skipping a recording can be attributed to poor signal.
One cause for poor signal is if you are using an amplified antenna(preamp is built in to the antenna). These are often powered with a power inserter/power supply. Many of these use a 5vdc power cube and a USB cable to connect to the power inserter. You can also power these by connecting the USB cable to an open USB port on your TV. When the preamp is getting its voltage out of the TV instead of the power cube, it loses the voltage as soon as you turn your TV off. This can result in poor recordings or missed recordings.