No sound from external speakers

Googling this subject reveals thousands upon thousands of similar problems, but I haven't been able to get my speaker sound back - they were fine 12 hours ago.

I use some simple external USB stereo speakers with my Asus laptop. It has Realtek sound, and I also bought a Xonar U7, through which I was channelling my sound quite happily until earlier today.

Headphones plugged into the laptop headphone socket work fine. They also work OK via the Xonar. The external speakers produce no sound at all however, whether plugged into the laptop speaker jack or into the Xonar U7: when I go into Control Panel/Sound and I can see the green sound indicator moving up and down as I play music however. Testing the speakers through 'configuration' produces no sound either. I tested the speakers themselves on a second laptop, and they work fine.

I have been through the various volume controls - nothing is set to mute. No problems show in Device Manager. I've rebooted and also used System Restore... Still got a silent laptop. All that works now, headphones apart, are the laptop internal speakers, which are pathetic..

Can anyone please help?

Many thanks,

Martin

PS. I have had this problem on and off for a while, though before I always managed to get the sound back, just by switching back and forward between the U7 and Realtek as the default, but that hasn't worked this time. I have posted before (I've just remembered - sorry for any duplication!!). Here is my previous post - but, it's not a problem with the plug this time:

External USB Speakers suddenly not working on my Asus laptop

Hi. Yes, sorry, my main PC is listed, not the laptop. It's an Asus X44, running Win7 Home Premium x64. (Is that enough info for current purposes?). The speakers have an audio jack and a USB plug. I have tried moving to different USB ports, to no avail.
Thanks.

I don't have a powered USB hub, but will try using a USB port from the other (Dell XPS) laptop to see what happens. I wouldn't be surprised if it is a USB issue - the ports on the Asus machine are very erratic. I don't think USB technology has really been perfected - every PC I have ever owned has had less than 100% reliable USB ports. Sometimes they work, next time they don't. This seems semi-permanent though...

Will test when I can and post back. Thanks.

As I have read elsewhere, this problem may just resolve itself, overnight. I am living in a rather out-of-the-way town in Sri Lanka (for work), so don't have recourse to the kind of tools and hardware I'd have back in London, but I'll do what I can before I post any 'results'. (Maddening to have invested in the Xonar and now not be able to sue it!!).

Actually, talking of USB, my main PC in the UK also seems to have issues: I use it for gaming only (MS Flight Simulator) and bought a Razer Tartarus keypad to go with my Saitek X52 flight control system (all just jargon unless you're a flightsimmer!). The Tartarus causes all my USB devices to lock up after a while. Doubtless a USB issue too.

Hi again. Been without internet for two days - provider had to come and fix it!! There's always some problem...!

OK, I tried powering the speakers from the Dell laptop, and hey presto, the sound was then fine on the Asus one. (Good idea, thanks!). I then juggled my USB plugs on the Asus to different ports and found that one of them is not providing the power needed, whereas one other is. The Xonar works well enough (so far) through the 'weak' port, in fact even via a non-powered hub (I wasn't using the hub for testing though I hasten to add, I was plugging straight into the laptop's USB ports) - so now all is working.

So, if I buy a couple if good powered USB hubs (one for this laptop, one for my gaming PC back in the UK), this should fix the issues, even though the powered hub would be plugged into a 'weak' port that will not support the USB device directly?

I also wonder why things worked fine for over a year and then suddenly stopped the other day...

Thanks for your help.

Martin