St7000 computer repair/purchase

[crwalsh]

Hi, I have an st7000 course computer - Z83-12v - that is giving an error "NO MAIN POWER" only when I switch from standby to auto. I've checked all the supplies to the computer and motor drive unit and all read above 12v (12.7v). There is no change in current when I switch from standby to auto. Q1: I did not see this error code in the documentation (it is NOT the same as "BATTERY LOW" alarm). What is triggering this message? Referring to the schematic on p. 65 and 69 in the service manual, Is it the 5v computer voltage or the 12v motor drive voltage or something else? Q2: this issue has appeared on a few cruisers forums and experts say a new computer is required. Is there anyone anywhere that fixes these things (e.g., Raymarine?) or anyone that sells refurbished systems?