Continuous discharge of power supply

1.Problem description:After installing the new PSU( power supply unit)on my 50 watt laser, the test pulse works well. However,when I turn the master power switch to the off position, the laser discharges. There is no arcing or visible problems with continuity.
2.Analysis:After the power supply is cut off, the capacitor has a continuous discharge process, so there will be residual power at the high voltage end.