Why doesn't my Philips CDR820 copy a disc when I press "copy cd" then the "yes" button?

If your Philips CDR820 is not copying a disc when you press the "copy cd" button and then the "yes" button, there could be several reasons why this is happening. Here are some possible solutions you can try:

1. Check the disc: Make sure the disc you are trying to copy is not scratched, dirty, or damaged. If it is, try using a different disc.
2. Check the blank disc: Make sure the blank disc you are using is compatible with your Philips CDR820. Check the user manual for compatible disc formats.
3. Clean the laser lens: If the laser lens is dirty, it may not be able to read the disc properly. Use a cleaning disc to clean the lens.
4. Update the firmware: Check if there is an available firmware update for your Philips CDR820. If there is, download and install it to see if it fixes the issue.
5. Reset the device: Try resetting the device by unplugging it from the power source for a few minutes, then plugging it back in and trying to copy a disc again.