Hi Al,
F801 on the local models lies just left of centre on the PSU, from memory. Bear in mind that IC501 is on the hot side of the PSU, so make sure you use the appropriate earth.
Interesting that the meter causes the relay to click. The IC is marked as STB CONTROL. A strange device with terminals marked D,S and C. Perhaps it is faulty and not being triggered, but couldn't say for sure.
On the ones I had, IC501 measured a bit of leakage out of circuit.
Bruce