They all have electronic converters in. A LED is typically 3 volts dc. A few passive components won't cut the mustard when they're connected to 230v ac.
But he will still prove it’s not a short
Perfect, that proves as much as needed at that point then. We are not trouble shooting the lamp electronics. Although should C1 break down on mains what would be the outcome of C2? And once that’s happened, max current flow?
Of course we are looking for a dead short, he is tripping out a 32A MCB the instant (I’m assuming) he inserts a lamp.
Indeed. I don't see a viable case for suspecting a current surge for this very reason. My money is on a problem with the MCB.As OP has said that it is the 5th lamp that trips the MCB - irrespective of which holder and which lamp that is, would that not rule out lamps and holders ? If it was all of them faulty then up to the trip point at 4 lamps there would be 25A flowing through the system on 0.75mm flex, which I am sure would be noticeable.
Plug in, first 4 lamps work fine, putting in 1 at a time. Get to number 5. Bang. Takes breaker out again.