The T753 is an AVR (I think) - the T163 is a pre/pro. I would venture a guess though that they have a similar design and if you take the cover off your 753 and they have NJM 4552 chips as the DSP - you could replace them as I did. (at least on the pre-out board where I changed mine).
Open it up and see what is in there....
I would recommend getting the service manual for your AVR before you start tearing into it. You can pick it up here for $15.00