I have a sony DSR11 that I had to have the firewire chip replaced, I was told by the tech @ the repair center as well as the sony tech, the chip gets burned out when the vcr is turned on before the computer, I was told that the DSR11 is more prone to the chip being burned out.
The procedure is, first turn on the computer on and then the vcr.
I had a power down situation for a short moment, and the vcr was not connected to the battery backup system but the computer was, soon after the power came back on, I lost VTR control, no more firewire connection, I did lots of research and I fount many similar situations, it is a costly repair.
I now am more careful.
Sigi