The 6655A power supply, when output is turned off will still allow the voltage setting to be increased using the Voltage knob on the front of the chassis. Once the output is turned on, the voltage will ramp to whatever voltage happens to have been set (based on the # of times the knob was turned clockwise). This can cause a surge/over-voltage if not carefully monitored.
Hi,
Thanks for the feedback. This is normal operation and not a failure. As long as the AC power is on, the knobs (both voltage and current) will adjust the settings. One thing that you could do is press the voltage button before the output on button so that you can double check that the voltage is set to the value that you expect it to be set to. Another thing that we would recommend is to make sure that your over voltage setting is set so that your device under test will not be damaged.
Let me know if you need any other information.