Fuse blowing on candle arch, causes?

passive

Hi,

I bought a plug in candle arch second hand, brought it home and plugged in on. Lights flashed on for a second then it went off, along with the other lights plugged in to the same multiplug. Tripped the switch in the fusebox too.

I checked the fuse, and it's a 3A like it's meant to be. I replaced the fuse with a working 3A fuse from another plug and nothing, won't turn on (in a different socket) but this time no trip switch problems. The 2nd fuse no longer works either now.

My question is where could the fault be in this case? If it was a problem with the multiplug, or too many devices plugged in, surely the fuse would have protected the lights? And why is the plug breaking a new fuse I add in?

Mostly I'm curious. I don't doubt it was working when sold to me, (photo taken of it working just before listing and seller reputable seller) and I know it blew out the second I plugged it in. Could bulbs moving too tight or too loose on the drive home be an explanation?

Final detail is that the first plug in the series now has black burn marks at the bottom where it screws in, and likewise on the socket for screwing it in.

Would appreciate any help or guidance to understand what happened here! Most importantly if the cause could be the multiplug my tree lights are in, that has to go.

brightspark

Pics of the black marks?

2011

Fuses should blow when too large a current flows through them.
Most likely this unit has a short circuit.