I had (and still have to some extent) a similar problem as reported in the link below.
http://www.remoterig.com/forum/index.php?topic=1694.0Although the power supply I am now using (Daiwa PS304) is working OK there have been the odd occasions where the FT-857 has locked up. I now have the FT-857 powered from the Daiwa PS304 and the RRC-1258 Remote powered from a seperate 2A 12V supply. Using DTMF control over the phone, I can remotely power on/off each power supply.
However, the ONLY way I can reset the FT-857 is to go to the remote site and connect the head-unit directly. Powering the FT-857 off and then on (whilst the RRC-1258 remains powered up) does NOT reset the FT-857.
Any suggestions appreciated although I will continue to investigate and report back any findings.
73's David G4ERW