My built in speaker ( Conexant HD Audio output) on my Acer D725 laptop is not working suddenly.I plugged my desktop speakers and was not working too. Any solution is highly appreciated. Thank you

Were the speakers part of the monitor or plugged into the side of the monitor.?..If so there may have been an amplifier in the monitor.. By replacing the monitor with one with no amplifier you have no sound.. The line output is not enough to drive the speakers ...you will need speakers with built in amplifiers that plug into a transformer plug and other green pin plug into the output on the computer.

Hello
If there is audio output from earphone sockets, the audio processign secion inside it is OK, and the fault must be either to its speakers or audio output section. A very skilled and expereienced technician can make it right. It will be best ot get this laptop repaird by its authorised service center for Dell at your town. Motherboard need to be troubleshooted.

How do you have the screen plugged in?
If via HDMI, audio should go to your screen, but you may need to output to speakers (that is, if your monitor does not have built-in speakers).
If indeed outputting via HDMI, make sure your computer KNOWS it's supposed to output audio through the HDMI port as well as the video.
Finally, you might just need to plug speakers/headphones into the monitor - most have an audio jack on the underside, by the stand.

remove the sound drivers then install the latest drivers

2. check if the corret sound out put is selected in sound option in control manger

Very few desktop computers have built-in speakers other than a small beeper on the motherboard, used for error codes at startup. You need some kind of external speakers which you plug in to the output jack on the computer's rear panel. Also, these need to be powered speakers, meaning they have a built-in amplifier. The computer's audio output signal is line level, and too low to drive speakers directly. You could plug in headphones, though, and listen to the computer that way until you get some speakers.

Hope this helps, and thanks for using Fixya!

Uninstall it then reinstall its missing a file basically, or your on safemode

You need to go to audio properties and change the output when using headphones. SPDIF is the high def signal that you would use if you had a home theater set without HDMI

For the first problem open your multimedia properties box under the audio tab you will have a sound recording device specified, check whether you have your device listed, usually you have your say ( Realtek HD Audio input or the respective company input device who supplied your audio drivers). If its not listed ten you might be having problem with the drivers or hardware you will have to call the service engineer to have to problem solved.

for the second one try the same solution. select the proper devices under the audio tab in multimedia settings.

Plugging headphones into the computer will disable sound output from the sound card by design.