Check input for multichannel..?

[kenjoswe]

Hi,
I have a Model12 mixer and suddenly Ableton wasn't able to receive on USB channel 1-10 any longer.
It only sends on 11/12.
I sent it to repair but they couldn't see that there was problem. They tested it on Logic and received on all channels.
Is there a way to check on a iMac if the problem is within the computer?

Kent J.