Check the mains isolator at the aerial(3 high voltage capacitor. or
1capacitor in ceramic insulator} for leakage if the chasis is' hot'.But
if the power supply is the type with 'hot &' 'cold',then check the
optoisolator,a high voltage capacitor in parallel with high resistance
[1M ]resistor between the secondary and primary of the chopper{"hot
"&" cold"} for leakage.Please use AVO meter with Resistance range at
1kohm to read for leakage.GODLUCK.