PG Music Home Forums General Discussion Off-Topic Laptop speaker quiet, but headphones work. Defective HP?

I'm pretty good on operating systems but not so good with hardware problems. Here's a quick story and if any of you can help, I would appreciate it.

Like many of you, I am the first call responder for friends. One has a six-month old HP laptop. The sound on the built-in speakers stopped working today.

He first tried calling HP support, which routed him to a support center in India. They took control of the computer remotely and installed lots of stuff on his desktop to no avail.

By the time I got home and went to look at it, my friend had spent three hours on the phone with support. Still no sound.

I checked the obvious, like Device Manager and the mixer. The system sounds showed an audio signal was being generated. He had no external speakers, so I tried plugging in headphones, and they worked. The headphone jacks had never been used. The online tech didn't think of that one...

Short of taking apart the case and checking for a broken wire to the internal speakers, does anyone have any suggestions? It's still in warranty, but there is the hassle of saving all his data and reinstalling if they just replace it.

Thank you.

Obvious probably

Checked system settings for correct output for speakers?
Double checked to make sure nothing is muted in the audio settings? Since this is a fairly new system, I know Win7 is a little more complicatd to check.

Some programs may load at boot that claim the sound routing, which may be a real pain to check.

Checked those, thanks. I've been on Windows 7 for a year, and it's actually easier than prior systems to check devices and settings.

Since the system sounds go to the headphone jack but not the speaker, I tend to think it's a hardware problem.

There may be some kind of fancy digital sensor which can know if headphones are attached. Such things are not impossible.

For instance, on my new HP Win 7 desktop with an XFi card, I was futzing with the line input getting an old little Alesis parametric eq setup as a mic preamp for digital conferencing with an Audix OM5 mic. Sounds better than cheapie computer mics, and much more durable. I was having an intermittent adapter/wire between the preamp and the line input, and every time I'd unplug the plug from the 1/8" XFi stereo line input jack, Win 7 would pop up a warning that nothing is plugged to the Line Input and the input had been made inactive.

That seemed kinda overkill to me, that every time I unplugged the line input plug Win 7 would turn off the input, and I'd have to revisit the control panel dialog and turn it back on as the default input after I plugged a wire back in. That is the software holding my hand way too much. If I want the line input to always be the default input, then what the heck does Win 7 or the XFi card care if there is nothing plugged in? Annoying.

Anyway, that has nothing to do with your problem, except to demonstrate that sometimes computers/drivers will go to a whole lot of trouble to solve problems that don't exist, and sometimes make it worse in the process.

Have also read that some Apple Mac hardware is smart enough (or perhaps that should be dumb enough) to detect if you unplug a mic or a line input, and automatically reconfigure the audio driver accordingly. Maddening.

So maybe your friend's computer is smart enough to know in the software whether a plug is connected to the headphone jack, and then do software-controlled auto-routing.

However, for many many years on many stereo receivers, boomboxes, portable radios, etc-- The speakers get muted in a much simpler fashion when you plug in the headphones. The headphone jack just contains some switch contacts. If nothing is plugged into the jack, then the audio goes thru the jack switches into the speakers. When a plug is inserted in the jack, it opens the switches and interrupts audio to the speakers. No software wizardry required. Just a simple switch in the jack.

Whether or not the laptop speakers are controlled directly by jack switches, or whether the driver software controls this-- If the driver software controls it, then there has gotta be a jack switch in there to tell the computer whether something is plugged in. So maybe it is a bad switch in the 29 cent headphone jack either way.

If it is a bad jack on the mobo, once you find the exact inexpensive replacement part, it is just a tedious hassle to fix it yerself, or pay a local repairman maybe quite a lot of money to replace the cheap part for you. If its 6 months old and under warranty, maybe make HP fix it?

Thanks, James. From my days running an electronics store 35 years ago, I just assumed the headphone jack was nothing special and had that disconnect in it like you described. That's way scary if there is some exotic sensor and software doing something as mundane as headphone routing. But thanks for the idea.

I forgot to mention, this laptop has two headphone jacks that function identically. That, to me, reduces the likelihood of anything wrong in the headphone jack switching. But what do I know?

Yes, it's under warranty but my friend doesn't want to lose the use of it during repair, nor undergo the aggravation of backing up and reinstalling into a replacement unit. I recommended he ask HP to exchange his hard drive into an identical unit.

Matt,
I doubt that HP will exchange the hard drive, not that it would matter, since the Authorization key is hardware dependent, and the hard drive is only a tiny fraction of the key.

I suspect that the speakers are bad, due to a hardware issue. It's no fun, but that's my guess.

Gary

Me too. Thanks, Gary.

I did not consider the authorization might not work. I thought perhaps the authorization would see the same hardware and give the same code. Thanks for the alert.

The possible reason they might want software control over headphones/speakers, is that the user can select software filtering schemes in the driver, which optimize for headphones versus big speakers versus tiny speakers. If the jack tells the computer that a headphone is plugged in, then the software can auto-insert a different dsp software driver module to 'optimize' for headphone output rather than speaker output.

Dollars to donuts that the actual power amp is the same for the headphone feed versus the tiny laptop speakers. The voltage drive is nearly identical for headphones versus tiny speakers, except that the lower impedance of the speakers delivers more power from the same volts when the speakers are connected. Inexpensive commercial 'home-studio' headphone driver boxes often use the same class of little half-watt or one-watt amplifier chips that are used in low-volume portable shortwave receivers or clock-radios or cheapie desktop computer speakers or whatever.

It strains credibility that a manufacturer would include two 25 cent amplifier chips on a laptop motherboard, if one amplifier chip could be used for both headphones and speakers. That is just wild guessing of course. No telling what a manufacturer would choose to do.

One innovative headphone driver was used in early-generation Mackie mixers. Maybe Mackie still uses the same scheme, dunno. Rather than using a possibly-lo-fidelity tiny amplifier chip, or an opamp with current-booster transistors, the Mackie mixers would wire several ordinary opamps in parallel to get sufficient current drive to push headphones. That circuit sounded pretty good IMO.

Which has nothing to do with your friend's problem. Just free-association chain-of-consciousness rambling <g>.

First best guess is that the internal connector for the speakers got jarred out of its socket in shipping.

Second guess has to do with the fact that most laptop speakers hook up with a 3-terminal connector that shares the Common (-) lead for both sides. If the Common connection is internally broken anywhere inside the lappy, both speakers go out.

I doubt this is a software problem because Matt has already been all over the doggone thing trying to get sound from the speakers.

I also doubt that there are any "sensing" circuits at the earphone jacks. Likely only a mechanical SPST set of switch contacts wired in series for the two headphone jacks.

There is only one Power Amp that is used to drive speakers or earphones, since the earphones are working, we know that the power amp is working. Since that is the case, here is yet another reason not to think that software is the cause. It would simply not be cost effective to use software to switch at the low impedance power amp side of the thing. That would and should take place at the lower power Line level, before the power amp.

Diagnosis (from a distance): The new owner should start the Return Authorization procedure and get it over with.

There is *another* way to approach this situation. Rather than return for service, the new owner should try to get the *dealer* to simply provide a replacement. Within 30 days of purchase, this is usually something that can be done and it eliminates the downtime without the lappy.


--Mac

Once again, many thanks to all who weighed in. It appears you all came to the same conclusion I did, that this is a hardware problem with the speaker or the speaker connection. I have recommended to my friend that he seek a replacement if the internal speakers are important to him, or just plug some computer powered speakers into the earphone jack.

Yeah, a loose speaker header plug to the mobo seems very likely possibility.

I have a system here that does as James mentioned; turning audio connections on/off as they are plugged or unplugged. Often guessing at what I want it to do. If I unplug the line in, it enables the mic, and disables it if I connect to line in. Same with headphone/speakers. Dunno if it is software or hardware triggered (I'm sure the hardware is involved obviously) but I was finally able to get it to stop popping up to tell me everything it was doing as a response to what I did. The system still does what it does, but I don't have to close the extra window anymore every time I connect something.

Only caveat was that now if I hook up a monitor using HDMI, it used to ask if I wanted to shut off the onboard LCD, now I have to go do that manually.

Tradeoffs for everything I suppose. just more rambling..

Hello. I am a longtime regular on Dell's Laptop Audio Forum and I just stumbled upon this thread. Here is some general info that echoes what has been said here about the audio jacks. This is for Dells but I think it is the same for HP if the computer in question has HD audio, because the specifications for HD are standardized. Off the top of my head I think the standard calls for reconfigurable jacks.

In the Dell's the jacks are "Universal Jacks" designed by IDT and are reconfigurable. When configured as headphone jacks they have a "sense pin" that triggers switching software, instead of the older mechanical switching system. When the sense pin fails then the system acts as though there is a plug in the jack. Sometimes the sense pin can be made to work if a plug is inserted and gently wiggled.

It can be a hard problem to diagnose because it is a hardware failure that has the symptoms of a software failure. I can tell a Dell owner how to verify that the sense pin has failed but don't know how on an HP.

If the sense pin has failed, the solution is to replace the jack, and that means either replace the jack daughter board if there is one or the entire motherboard if the jack is mounted directly on it. Because the repair can involve a lot of money it is a good idea to have it fixed while still under warranty.

Hope this was of some help. I am reading a lot that is helpful to me on this forum.

Hi, Jimco -

Are you the same Jimco that was involved in the long discussion over the availability of stereo mix and audio monitoring a few years back when Dell shipped Windows Vista on their systems and their driver didn't provide it? I was one of the ones that complained bitterly about that, and in the end returned the nice Dell laptop I had purchased.

Welcome to the forum here and hopefully you can learn even more.

Jimco, thanks for this info. I still doubt it is the jack itself, since there are two on this laptop and they both behave the same. Also, they have never been used until I just tested them.

Matt,
I could easily believe that even with two headphone jacks, according to what Jimco has said, that it might not be the jacks at all, but a daughter board, or the sense signal to the HD audio chip. In fact, I would suspect that it was the chip itself, not the jacks.

Can you tell me what HP computer he has?

You might also want to look at this:

https://www.youtube.com/watch?v=tLlDLVXvRA4

Gary

Thanks Gary. Hadn't thought of that, either.

I'm not in town now; when I get back Monday I'll see what model it is.

_________________________________________________________________

Oh, man, that video! Just push the magic button!

Really something.

John, yes it is I. Sorry to say that Dell has not changed for the better but then neither have I so I am still manning the laptop audio board.

Matt, it's either the jack, the speakers, or a loose/broken connection to the speakers. For what it is worth, on the Dell models with 2 headphone jacks when the sense pin becomes a problem then in the audio control panel one of the jacks will be marked that it is "in use". [The purpose of the 2 jacks on those models is that they and the mic jack can all be configured as 5.1 surround line-out jacks.]

In the Dells there is a bootable diagnostic partition that runs outside of the Windows operating system. If the speakers work in that diagnostic environment then one knows that there is not a hardware problem with them and that leaves the jack as the culprit (or software but by this point one would have already reinstalled the audio driver and doubled checked configurations etc). That pretty much nails it but the diagnosis can be completely confirmed by restoring the computer to its original factory configuration which eliminates all possibility of a software issue (because the speakers did originally work in that configuration).

Conversely, if the speakers do not work when running the bootable diagnostic test then that confirms that there is a hardware failure, and one knows the failure is after the signal reaches the jack so the speakers or connection is the culprit. The possible failure of the sense pin does not affect the way the Dell diagnostic test works (ie the speakers will be tested whether or not the sense pin has failed) because the switching software is part of the Windows driver and Windows and the drivers are irrelevant to the test. So if HP has an equivalent diagnostic partition it could prove useful. If there is one then HP support will probably have your friend use it anyway before they authorize repairs.

Thank you, Jimco. I will look for that.

I will also try pressing the magic 'button' as in Gary's video.

As a tech moderator on a general computer help forum, first I confirm Jimco as correct and that the most likely fault being the common return or ground pin from the speakers to the motherboard, or jack daughter board being the source of the fault, not been inside a HP so don't know exactly where the speaker wires go to from the speakers.
Even though the machine is under warranty and should go back for repair, if that is to be avoided, then a careful dismantle and visible check will show if the plug has come off the board.
For general laptop dismantling and repairs advice have a look here--

http://www.laptoprepair101.com/