I am looking for the part to fix my canon xlh1 fire wire. I was told this is the part a need DG3-1253-000 000 C 1 PCB ASS’Y, HP
At this point the XL-H1 is over a decade old. Your best bet for finding parts is likely either from the Canon Parts Order Desk at (866) 481-2569, or if they don't have it, then checking with one of the major Canon repair centers to see if they have any parts left.
The Canon Parts Order Desk will be able to tell you for certain if they no longer have more replacement parts for the XL-H1's firewire PCB.
Another possibility if parts aren't available is to purchase an HDV deck and transfer tapes via a playback deck rather than via the camera itself. If you need live capture instead, an HD-SDI capture device such as a Black Magic Intensity or DeckLink card could do the job of uncompressed live capture.