iMac/new logic board/Garageband problem.

[Brownie58]

Hi all,

I have a 20" iMac i bought just before the new ones came out. Never had a problem with Garageband. When the logic board went bad, i had it replaced.

The problem: Since getting the new board, I cannot get a signal into GB. I have changed GB settings for internal/external mic, and the Mac system preferences for the same. I get no signal with either internal or external mic. I called the store, spoke with tech support, they tell me it could be software or a hardware issue (that certainly narrows it down).

Wondering if anyone has had similar problems, and what some possible causes/solutions might be. Not crazy about reinstalling the OS, but if I have to I will. thx.

 

[dgatwood]

I have a 20" iMac i bought just before the new ones came out. Never had a problem with Garageband. When the logic board went bad, i had it replaced.

The problem: Since getting the new board, I cannot get a signal into GB. I have changed GB settings for internal/external mic, and the Mac system preferences for the same. I get no signal with either internal or external mic. I called the store, spoke with tech support, they tell me it could be software or a hardware issue (that certainly narrows it down).

I am assuming that you don't see any signal level in the audio preferences pane when you choose either input. If you do see a signal there, then Garage Band is hosed somehow. I would be really surprised if you did, though, as your description screams "bad logic board".

If you reinstalled the OS in between, installed a software update or firmware update, reinstalled garage band, switched to a different hard drive, etc. then yeah, it could be either hardware or software... but if the only change was the replacement of the board, Occam's Razor covers this one. The board's a dud.

It's pretty much guaranteed to be the logic board itself. I don't even think it could be a connector board problem, since you said it doesn't work with the internal mic. That's a pretty sure sign that the audio chip itself and/or some of the analog electronics are shot.

Sorry you got a dud. If you had the repair done at a store, take it back, tell them that your audio input hasn't worked since they swapped the board. They'll probably take one look at it and swap the board again without giving it a second thought.

Otherwise, either take it to the store or call AppleCare, and they should be able to take care of the problem. Be sure to explain that it worked before they swapped the board and stopped working immediately afterwards so that you eliminate any doubt in their minds that this was the direct result of the board swap.

One last tip: if you have AppleCare, at least for desktops, you can generally ask for an on-site repair visit (at least in the U.S.---not sure about other places). With an on-site visit, they'll come out, dismantle your machine, replace parts, and put it back together. You can test it out right there in front of them and if it doesn't work, they can order whatever parts they think are needed to fix it. Highly recommended. At least where I am, on-site repairs are handled by Qualxserv, and they seem to do a reasonable job.

 

[Brownie58]

I am assuming that you don't see any signal level in the audio preferences pane when you choose either input. If you do see a signal there, then Garage Band is hosed somehow. I would be really surprised if you did, though, as your description screams "bad logic board".

If you reinstalled the OS in between, installed a software update or firmware update, reinstalled garage band, switched to a different hard drive, etc. then yeah, it could be either hardware or software... but if the only change was the replacement of the board, Occam's Razor covers this one. The board's a dud.

It's pretty much guaranteed to be the logic board itself. I don't even think it could be a connector board problem, since you said it doesn't work with the internal mic. That's a pretty sure sign that the audio chip itself and/or some of the analog electronics are shot.

Sorry you got a dud. If you had the repair done at a store, take it back, tell them that your audio input hasn't worked since they swapped the board. They'll probably take one look at it and swap the board again without giving it a second thought.

Otherwise, either take it to the store or call AppleCare, and they should be able to take care of the problem. Be sure to explain that it worked before they swapped the board and stopped working immediately afterwards so that you eliminate any doubt in their minds that this was the direct result of the board swap.

One last tip: if you have AppleCare, at least for desktops, you can generally ask for an on-site repair visit (at least in the U.S.---not sure about other places). With an on-site visit, they'll come out, dismantle your machine, replace parts, and put it back together. You can test it out right there in front of them and if it doesn't work, they can order whatever parts they think are needed to fix it. Highly recommended. At least where I am, on-site repairs are handled by Qualxserv, and they seem to do a reasonable job.

Thanks for your reply. I read it after you posted, but didn't have a chance to reply until now.

For whatever reasons, everything seems to be working properly. I did nothing any different from what I had posted previously. It just started working. I have no explanation, but I'm glad to be up and running! Thanks

 

[dgatwood]

Thanks for your reply. I read it after you posted, but didn't have a chance to reply until now.

For whatever reasons, everything seems to be working properly. I did nothing any different from what I had posted previously. It just started working. I have no explanation, but I'm glad to be up and running! Thanks

Weeeeird. Gremlin?