The Sony AV-3600 service manual was what I needed for the repair of this unit
Thanks for the good service
Dave
Text excerpt from page 66 (click to view)
Power Supply CBA Top View
NOTE: The voltage for parts in hot circuit is measured using hot GND as a common terminal.
Because a hot chassis ground is present in the power supply circuit, an isolation transformer must be used. Also, in order to have the ability to increase the input slowly,when troubleshooting this type power supply circuit, a variable isolation transformer is required.
