Help with ICL power supply fault (Farnell SMPS)

The prolem is that if this is like most small SMPSUs, then almost all the 'interesting' circuitry (oscillator, etc) is on the mains side of the isolation barrier. And therefore you can't just connect a 'scope to it, not unless you like shorting out the mains via one of the rectifier diodes and the earth (ground) lead of the 'scope. The right way to do it, of course, is to use an isolating transformer, but not everybody has one of those in the workshop. I certainly do not recomend 'floating the scope;' (removing its earth lead so the 'scope chassis can sit at half mains voltage, or whatever), even though this is suggested in one service manual I have if an isolating transformer is not avaialble. I have this objection to large metal ohjects sitting at dangerous voltages. -tony