Hello Jonathan,
 
The oxidation might be removed by fluxing the bottom of the device and reflowing it. If that doesn't work, you may have to reball them. We build such systems. Please visit our website and call/e-mail if you have any interest.
 
Regards,
 
Ed Popielarski
QTA Machine
10 Mc Laren, Ste D
Irvine, Ca. 92618
 
Phone:949-581-6601
Fax: 949-581-2448
Cel: 949-337-2578
 
WWW.QTA.NET