KiT 6550 ECF 80 Pin 6 Voltage

[Greg.]

Yep, what Bob says. If you want to be 100% sure of a components measured value, always lift one leg and then measure to be sure you are measuring it in isolation of the surrounding circuit.

Of course, with knowledge, you’ll know when or when not this approach is needed, but if you remain in the amateurs club like me, this is the easiest and best way.