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myxomatosis · Jan 13, 2005, 01:47 PM

Hey guys, I just started getting astrange problem with my G4 1gz pb (titan.). When I listen to it through headphones, I only get mono output. The people at the mac shop told me it was my logic board (assumng it to be a hardware prob with the headphone jack) but I tried it with an external sound card via USB and the problem is still there.....any ideas what could be causing this? Software or hardware? I really hope it is not my logic board ($1000 to replace the thing)....please if you guys have any info please let me know.Cheers and thanks a bundle-Myxomatosis

Spheric Harlot · Jan 13, 2005, 07:54 PM

Do you really mean mono?

I assume you mean that only one channel is working (i.e. either right or left). That's not mono, that's just one channel not working.

If you're getting the same symptom via a USB audio interface, then it's rather unlikely that the motherboard is at fault.

Have you checked the sound settings in the System Preferences? Sometimes the stereo pan slider would get moved over to one side, resulting in uneven stereo balance.

This bug has been fixed in one of the newer system updates, IIRC.

-s*

waffffffle · Jan 13, 2005, 08:10 PM

I have found in the past that my panning would be screwed up without even touching it. I was able to straighten it out in Audio MIDI Setup.

Anubis IV · Jan 13, 2005, 09:15 PM

Yeah, when I read that my first thought was whether or not you actually mean "mono" when you say mono. If it's only coming through one speaker rather than two, or is only coming through one headphone rather than two, that just means it's on one channel only...that doesn't mean mono. Mono is entirely different. Sorry if this is a bit patronizing and stuff you already know...just want to be sure we know what the problem is before we diagnose something.

Anyway, if it's the one-channel problem, just check your sound settings like the other guys said and switch your pan/balance back to the middle instead of left or right.

myxomatosis · Jan 13, 2005, 11:03 PM

Thanks for the input guys...
I do stand corrected...it is not mono in the true sense...the right side headphone is dead...left side works fine.
When I play it through my USB (roland UA-30) interface, both headphone speakers yield sound fine but are only splitting what would normally come through only the left speaker in half...if that makes sense.
My internal speakers work fine. I've checked the slider in Sysprefs and when I put it all the way to the right, no sound. I'm running a fully updated version of OSX panther. ...haven't tried to reinstall. I am glad that my suspicions about the mother board seem to be holding up....didn't make sense that both the USB and headphones jacks were faulty with the same symptoms (which is what the mac guys tried to tell me...I now have it back with them, this time with USB interface in tow!). I only took it there in the first place because I thought they'd have a much better diagnostic set-up then apparently they really have...Anyodd any more info would be super...Cheers and thanks for your time guys/gals.
-myxomatosis

Spheric Harlot · Jan 14, 2005, 06:40 AM

futz around with the driver settings in Audio/MIDI setup (in Applications/utilities) and see if it fixes things.

to be frank, your USB interface mirroring the left channel in both headphones sounds like a broken or not fully inserted headphone plug.

My bet is that the stereo problem is a CoreAudio-related issue, so play around in A/Msetup and report back.