Nobody has mentioned that the T-Unit MK1 and MK2 ARE in fact the same board. The T-Unit MK1 uses the same harness as the MK1 Y-Unit for the sound board, but MK2 uses a different sound board, thus requiring a different set of sound cables.
To answer the question, no the sound board and cables are different between MK1 and MK2, but the main boards are the same as long as you are talking about a T-Unit MK1.
Just wanted to say.