I purchased a pair of L1m2 with double bass from the local Bose store, along with one T1. I decided to add another T1, but (gasp) bought it on eBay. Of course, it showed up damaged. The right selection knob under the LCD turns just fine, but when I push it to make a selection, it does not give the tactile feedback of being pushed (no "bump"), and requires a very hard push to actually register the selection. Is this something I can fix myself? Thanks!