How to Troubleshoot a Sony CDX-MP40

Written by darrin meyer
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to Troubleshoot a Sony CDX-MP40
Try troubleshooting your car stereo before tossing it out. (Hemera Technologies/ Images)

The Sony CDX-MP40 is an XM-ready AM/FM/compact disc car stereo with features including a flip-down detachable face, 18 FM and 12 AM station presets, MP3 and CD-R/RW playback capability and blue-tinted LCD display. It is designed to be a versatile, high-performance mobile audio component, but as with any other electronics product it is not exempt from the occasional glitch or larger malfunction. When an issue arises, there are possible solutions to try on your own before driving to a car stereo service centre.

Skill level:
Moderately Easy

Other People Are Reading


  1. 1

    Press the "Volume Up" button to increase the volume if you do not hear any sound. If that does not solve the issue, press the "ATT" button to cancel the attenuating feature. Attempting to play MP3 files from an incompatible player can also result in a lack of sound. If you do not hear a beeping sound when pressing buttons, press "SEL" and the "6" button together to see if the beep feature is turned on. However, the beep is automatically disabled if the stereo is connected to an outside amplifier.

  2. 2

    Press and hold the "Off" button to turn the display back on if the display does not appear. Remove the front panel and clean the connectors with a cotton swab dipped in alcohol if you still do not see the display. Check the fuse assigned to the stereo in your car's fuse panel to see if it has been blown and needs to be replaced.

  3. 3

    Check and tighten the battery cables of your automobile, and check the wiring connections to the stereo (if you can obtain access). Do this especially if the stereo will not turn on or if certain memory functions have been reset, such as the clock and station presets. Also, pressing the "Reset" button behind the front panel may be the cause of the memory functions to be reset. Store the settings again into the system's memory so they don't get erased.

  4. 4

    Press "Eject" to see if a disc has already been inserted if a CD refuses to load. Also, ensure that you are attempting to insert the CD face up. Check the condition of the disc itself if playback does not begin or if the audio freezes or skips, and wipe off any dirt or grime and buff out any scratches before reinserting. And, know that only MP3 files on CD-R and CD-RW recordable discs are compatible with the player, and that anything other than those formats cannot be played.

  5. 5

    Press and hold the "List" button for more than two seconds if the display appears as a series of long dashes. This indicates that the stereo is in disc name edit mode, which is also activated by pressing "List."

  6. 6

    Press the "Reset" button located behind the front panel if a CD refuses to eject and there is no response with any other function keys. This will reset the system, but you will then need to reset the various stored memory settings.

Tips and warnings

  • Consult the manual supplied with the CDX-MP40 for information on the various features and options available with the car stereo, as well as how to access and manage them.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.