How to restore sound on my 18in flat screen with a dvdk

1) you must the headphones in any radio, for to see if the problem they are.

2) if they are o.k go control panel use the utility system restore put the last date that you know that was working.

God bless you

restore using the utility system restore go to control panel, and put the last day that you know was working good.
However you can use cleaner contacts solvent and fix it. Open in control panel the icon sound and use the tabs for headphone, and test the troubleshooting.
You mus sure that you headphone is good, try to test in another computer or CD, DVD. etc
God bless you

i would take the button bar of and check to see if the cable is off to one side its a flat ribbon cable sounds like it is a little sideways that will make that happen there is a little clip be gentle undo it a little bit and straighten it out

If the headphone jack socket works the audio output for the set is good, I suspect a dvd etc will also work if connected to the rear input audio and video jacks.

This does not leave too much, headphone jack dirty or defective, speakers for whatever reason are switched to off in the main menu.

the sound for the headphone socket if it is built into the set is the same audio going to the speakers.

Verify there is nothing plugged into the headset port, including headsets, headphones, or adapters.
Original iPhone only: While on the Home screen, adjust the volume buttons. If you see the icon below, indicating that headphones are attached, there may be debris in the headset port:



To remove debris in the headset port, try connecting a pair of headphones to the headset port and then remove the headphones. Repeat this several times.
If you have paired with a Bluetooth headset that is nearby, either use the headset or turn Bluetooth off (choose Settings > General > Bluetooth).
If that doesn't work, try restarting the iPhone. Hold the Sleep/Wake button until "slide to power off" appears. Slide to power off your device. When it is off, press the Sleep/Wake button to turn it back on.
If restarting the iPhone doesn't resolve the issue, try restoring the device.

Some users who have recently updated/restored to the new iPhone firmware 3.0 have reported to have got into a problem where their phone randomly doesn’t ring when there is a call nor does the keyboard or slide to unlock button sound anymore. I got into this problem as well after unlocking and jailbreaking my iPhone 3G with firmware 3.0, my iPhone suddenly stopped ringing on calls randomly, resulting in missing a lot of important calls.
So if your iPhone isn’t ringing sound on calls, or if you are unable to hear the keyboard or slide to unlock click sounds, then try the following fixes before you panic and call Apple support:
Fix #1: Push feature is currently not working properly on jailbroken iPhone’s. If you have installed an application which supports Push Notification System then try disabling the Push feature as it may solve the problem.
Fix #2: Try Resetting the iPhone: Settings > General > Reset > Reset All Settings. This will reset your phone’s setting to factory defaults. Your contacts, calendars photos and any other data will stay intact.
Fix #3: There is a slight possibility that your iPhone’s headphone jack may have got some dust or rust which is causing the phone to think that the headphones are still plugged in when they actually aren’t. Try blowing out air in the headphone jack or try plugging the headphones in and out repeatedly. This trick may solve the no sound problem.
Fix #4: Restore/Update you iPhone back and start afresh: If the above solutions doesn’t help in solving your problem then you will have to start from scratch by first restoring your iPhone to the the original firmware
3.0 from iTunes, jailbreak it using redsn0w and then finally unlock(3G users only) it using ultrasn0w. This has fixed my problem.
Fix #5: Install Insomnia from Cydia: Install Insomnia as your last resort. When you press the power button on the top, iPhone goes into sleep mode after 30 seconds, in the process turning off your WiFi, sound and other stuff. When Insomnia app (available for free from Cydia) is enabled, applications will keep running and sound & WiFi will stay connected when the screen is off. This should fix your problem if all of the above solutions have failed to fix it.

I had a similar problem, turns out that one of the jacks was dirty. I used these instructions to clean it and it worked. Try at your own risk though...http://www.instructables.com/id/How-to-Clean-a-18-3.5mm-Headphone-Jack/

As far as i know, all Rosen in-car dvd players come with IR (infra-red) headphones so the sound is transmitted that way rather than using a lead from the headphones to the unit, therfore no sockets are neccessary!
Hope this helps....

You need to change the mode on the stereo to dvd. The dvd sound comes through the vehile stereo. I just bought a used one a week ago and had the same problem, eventually figured it out.

sounds like the dvd players set for differant picture format like full screen compared to wide screen settings. Look in the Menu of the tv as well as the dvd player