I got a new to me hd-a35 off the bay and it was DOA (the seller was a real jerk) so I took the power supply from my hd-a3 and put it in the hd-a35. It's working for now but should I be worried about damage to the a35 using the hd a3's power supply?
Most of the innards of each generation's players are the same. I transplanted an A3's drive into an A30 player with no problems. Firmware loads are what you have to watch out for, as loading firmware for the wrong player can brick it!
The A30 can be upgraded to bitstream Dolby Digital Plus and DTS-HD Hi-Res but not TrueHD or Master Audio- it won't put out any sound when playing those in bitstream mode. I was mainly talking about the power supply and disc drive, the main boards of course will be different.