No sound without headphones in dellvenue pro - Dell Venue Pro Smartphone

your device speaker or head phone socket is defective.

Is it a fan noise?

No the headphone jack doesn't disable the speakers. There are two switches in the lower middle of the receiver that are labeled speaker A and B. Pushing one of these should disconnect the speakers from the receiver.

go to system preferences then click on sound, then make sure the "use audio port for" is set to sound output.

you can not hear the sound

record on mono, not stereo..unless for playback

There is an internal switch inside the actual 3.5 mm headphone/speaker jack. When you have either headphones or speakers plugged in, it automatically switches to external. FYI: Macs are also notorious for getting 'stuck' in this mode (external) and I've had to walk numerous people through the steps to correct this. My Macs are definitely not excluded :) I hope this helps.

You are getting low volume because there is no amplifier in those speakers. Computer speaker sets are powered -- there is an amp in one of them them which drives both speakers -- a computer audio output without an amplifier will only satisfactorily drive headphones.

Koss has a no questions asked guarantee on some of the Pro-4 series, all you pay is shipping. Call the repair department to check.

please check your speakers, try to insert headphones and hear if u can hear any sound, try to install drivers
if u can hear the sound with headphones means there is a problem with ur internal speakers