Is this a psu or main board fault?

I have a TEAC T22DVDB19A that would not power up. I have had a look at the PSU & there are no obvious problems. What we have discovered is that if you touch the live mains or the heat sink with something capacitive (probe from multi-meter, insulated screwdriver etc) the set powers up into standby and appears to operate OK switching on & off OK. If mains is unplugged, original fault presents again. Also when the set switch is used to turn off the standby LED flashes 4 times, is this a fault code and if so what does it indicate?