Suddenly... avrdude: stk500_recv(): programmer is not responding.

Development Tools IDE 1.x
1

I am running Arduino on a iMac running 10.7.5.
I have been writing and upload sketches for about a year now on this machine.
Today, it stopped.
I am now getting the error : "avrdude: stk500_recv(): programmer is not responding."
I have changed USB cables, tried multiple Arduino Uno boards, restarted the Mac, ... no luck.

I can upload to the same boards via my Macbook, using the same cable, so it is not the boards or the USB cable.

Could it be my Mac's USB?
Any ideas?

2

I assume the reason for running Lion is do to age of the MAC, what version of Arduino IDE are you running?

To help trace events you say it stopped today, when was last working period and what has been loaded or done on the MAC after last time the board worked.

When board is plugged in what is showing under USB using MAC's System Tools (are you seeing board connect and disconnect).