On 2011 iMac, External Altec Lansing speakers no longer work after upgrading to Mountain Lion. They DO work on a lenovo machine but not my imac

Question

On 2011 iMac, External Altec Lansing speakers no longer work after upgrading to Mountain Lion.
They DO work on a lenovo machine but not my iMac. reset Pram - no luck. took speakers from wife's desktop, they
do not work when jack plugged into my iMac - Sys Prefs "SOUND" only lists "internal speakers/ built in" as available options.
I used my altec lansing speakers on 3 macs including this one for 5-6 years.....now with Mountian Lion I can only get internal speakers???
Ideas? Any/All help would be greatly appreciated - been going nuts with this for 2 days now.

Answer 1

Hi,
When you start Messages fro the first time you are asked for an Apple ID
When this is verified and entered it appears in Messages Menu > Preference > Accounts and is Enabled.
The App should have also picked on on those iChat Accounst you had before.
These should be Enabled if they were when you last used iChat.
Exactly which "Accounts" are logged in can be seen in Message Menu > Accounts and will include the iMessage "Account" and Bonjour.
In the Window menu you will see CMD +0 for the Messages window and CMD+1 for the "Buddies" window which is a combined list at this stage.
Go to the Preferences > General Section and Untick the "Collect all accounts into one list".
This will give you separate iChat type Buddy lists.
You can check if that account/Buddy list is set to Invisible or if in the Preferences > Accounts > Security you have settings that will block some people from seeing you as On line.
You are saying Buddies can see you as On Line which implies they are still sending to your AIM based Names (@Mac.com is a valid AIM Screen Name)
I am not sure from your post if you are trying to iMessage their email IDs thinking they are Apple IDs and that they are using Messages as well.
There is no Buddy list for iMessages side
No-one can tell you are "On Line" until they have your details in the "To" spot in Messages with the correct iMessaged contact info (iPhone Number or Apple ID)
Obviously an Apple ID can be an email or look like one.
In some cases they are also valid AIM Screen Names as well.
In the case or the @mac.com name you may have linked this Apple ID to iMessages as well.
11:31 PM      Saturday; August 11, 2012
Please, if posting Logs, do not post any Log info after the line "Binary Images for iChat"
  iMac 2.5Ghz 5i 2011 (Lion 10.7.2)
 G4/1GhzDual MDD (Leopard 10.5.8)
 MacBookPro 2Gb (Snow Leopard 10.6.8)
 Mac OS X (10.6.8),
"Limit the Logs to the Bits above Binary Images."  No, Seriously