Comag sl55 voltage leak

[Joca]

What is likely to allow a voltage leak on a psu?

[Guest]

i have 130 volts on an alumminium heat dissipator. Is this normal?

[vtech]

In general heatsinks are usually at zero potentional, however depending on the circuit design, it may easily be sitting at any potential where it may have direct contact with a collector casing of a transistor or body of a regulator tab.

Your ground reference point is critical---not all heatsinks are always at ground potential. As in example in chopper supply application you have cold & hot ground which will give different readings

---no way you could have 130 volts leakage & not have something short out/blowup etc.

Term leakage is usually in mili/micro range.