Not working. Broken wires on electronics

Nice set of 80 LED lights worked well last year. Dug them out, plugged in and nothing.

Opening up the only box on the wires, it containes a small PCB from which the wires have come detached. There is nothing complicated about the PCB - power comes in, there are 4 diodes and the lights are connected to the other end.

So I soldered the detached mains lead back, plugged it in and this part at least seems to work (I get 240V across the power in terminals and 217V across the connections to the lights.

There are 4 wires connected oin a strand to the lights. 3 have become detached. It looks originally as these 3 wires were connected to the same terminal and hte fourth wire (still connectged) to the other terninal.

So I expect 3 strands of lights but 3 doesn't go into 80 so maybe its 2 strands of 40? Either way, its odd because the end LED has one wire atached to one terminal and three wires attached to the other terminal which suggests 3 strands?

So plug the lights and tried connecting each of hte three loose wires in turn to the other ternnial . Sadly no signs of life

Any suggestions as to how I might ry to get these working?