Calling all Mac Gurus...Sound has stopped working

scottlwl

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Hi all,

I need help.

Up until yesterday I have been using with out fail a 2008 iMac 2.66ghz to run plex for media centre duties. I connect to my onkyo 605 thru optical from the iMac. Never an issue.

But last night I turned on plex to find I had no sound. I then tried iTunes, no sound, spotify- the same.

I unplugged the optical cable from the amp, light is coming through. Tried the other end and sound comes through the speaker on the iMac.

I then tried headphones through the same socket and they worked fine. weird. Cable maybe?

I plugged the optical into my macbook and it worked fine. Even weirder.

The only thing I have done is plug in a usb sound card to see if it worked on the mac before I lent it to someone. I didn't go into the settings. That is the only thing I can think of that has borked it. I haven't got it plugged in now btw.

I have been through the preferences and audio midi setup thingys but can't seem to see anything glaringly wrong.

When the cable is plugged in the volume control greys out so it knows it is being plugged in. I am just not getting any sound.

Anyone got any bright ideas?

I have a time machine that has a full back up on the Macintosh HD shall i use that?

Please help gurus!!

Scott
 
It's not unusual from my experience to have the sound pref be a little 'sticky'. It may just be a restart will refresh things. I know it's a bit of a basic thing to try, but often it does cure all ills of that type.

Might also be worth just looking at the sound preference pane in the time machine backup to see if there are any obvious differences too. I wouldn't have thought you would have to resort to using a backup.

Graham
 
Thanks Max for taking the time to answer. I know people are busy. It is so frustrating though when things go wrong for no apparent reason. Great call to look at the settings in time machine. I deffo try that when I get home.
 
An old fix used to be to launch GarageBand and then quit the app, worth a try.

However this sounds like an issue I had, the audio out combines the analog and optical and the switch is inside, this sometimes sticks and can be cleared by plug/unplugging a few times. On a MacBook it's serious as the connector is mounted on the mobo not sure about an iMac though. HTH
 
Thanks Max for taking the time to answer. I know people are busy. It is so frustrating though when things go wrong for no apparent reason. Great call to look at the settings in time machine. I deffo try that when I get home.

My pleasure. Not everyone has alternative sources for their sound, so may not have even looked at their sound prefs before. Hope you get it sorted.

Graham
 
An old fix used to be to launch GarageBand and then quit the app, worth a try.

However this sounds like an issue I had, the audio out combines the analog and optical and the switch is inside, this sometimes sticks and can be cleared by plug/unplugging a few times. On a MacBook it's serious as the connector is mounted on the mobo not sure about an iMac though. HTH

Ooh, This sounds interesting. I am remembering accidentally opening Garageband. Hmmm I hope it isn't a Mobo problem. Could be very expensive. Thanks so much for the suggestions I will try tonight.

My pleasure. Not everyone has alternative sources for their sound, so may not have even looked at their sound prefs before. Hope you get it sorted.

Graham

So I can open Time Machine, then Open the sound preferences within time machine? It is all very odd. And frustrating. Almost thinking of launching it through the window last night.
 
Not at my Mac at the moment, but try opening Midi pref pane and changing settings from 44Mhz (I think) to something else. Come out of Prefs, go back in and change it back.
 
Not at my Mac at the moment, but try opening Midi pref pane and changing settings from 44Mhz (I think) to something else. Come out of Prefs, go back in and change it back.
That's the same as running GarageBand.
 
Thanks so much guys for taking the time to try and help me. Its that bad I have been looking at different solutions...i.e. appletv or mac mini. I hope when I get home tonight I will be able to fix this with one of your ideas.

Fingers crossed
 
Bad luck, take it into an Apple store they'll diagnose the problem for you.
 
Just to be clear here, is the lead from the mac putting out light when playing sound?

If so, could it be a setting on the amp?

Hope it's not your mac's optical port playing up.

Graham
 
The Optical port is outputting light. I have tested the cable at amp end - Light is there, Mac end by plugging it into the Macbook and it works fine with that.

I am going for a complete re install tonight then using a time machine back up to restore my stuff. Wish me luck. If it still doesn't work after that I will have to take it to the store.
 
Wouldn't it be quicker to use Time Machine first, before doing a clean install?
 
I don't know what I am doing if I am honest. I have had this iMac since 2008 and it has never gone wrong/crashed/frozen. By now I would have had to rebuild a PC loads of times. So now it is failing me I am finding it hard to know exactly what to do.

How do I re-install from time machine?
 
essentially, you make sure you have a latest backup, install from your install disc and then at some point towards the end of the installation, you have an option to restore from a time machine backup. However, if the thing that has broken your sound is a configuration issue, you'll break it again by restoring from your time machine backup.
 
Always worth doing is launch disk utility (from applications > utilities folder). Then click on the hard drive on the left and then pressing 'repair disk permissions'. That might take a little time, but might shake it down.

If that doesn't work, if there is a flakey setting, it may be cured by 'zapping' the PRAM. This essentially clears out any custom settings to default. Often it can help with things like this.

Just reboot the machine holding down the command, option, and 'P' and 'R' keys until it chimes a second time and then let it continue (you can take your hands off when it chimes the second time).

These are well worth trying before you do anything more extensive.

I did read that sometimes if it is set to 5.1, it can throw it. Maybe try to select stereo if you can access it at all. And very, very unlikely, but you haven't got it on mute have you?

Really hope you don't have to resort to re-installing. That would be a pain.

Best of luck.
Graham
 
PRAM didn't work, trying the permissions now.

Next step install, then genius bar....wish I knew what I was doing
 
Right,

I have gone back (with install disk and time machine) to last week. But it still isnt working. This points me to a broken bit of hard ward inside the iMac.

Can I swear???

B****x!


I guess I will have to see if it is cheaper to fix or to buy mac mini to do the plex duties and keep this for the family computer
 
have you tried install disc on it's own? i.e. don't restore from time machine in case you are restoring something that is muting the sound.
 
Yes I have and still the same. It must be a hardware issue.

Its going to be fun carrying it through town to the apple store today
 
Yes I have and still the same. It must be a hardware issue.

Its going to be fun carrying it through town to the apple store today

I trust you have a genius bar appointment or you probably won't get seen. I'd be quite surprised if you got an appointment so soon. You do it online.

If you ring the store, you usually get the opportunity to speak to tech support. They are pretty good and can make some useful suggestions to diagnose the problem over the phone. Then you will have a case number and they can make an appointment to take the machine in should it be necessary.

I'm still confused as to why it is putting out light (ie sound) and still not working. But not sure what else can be done at this point.

Graham
 

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