If you suspect the cable wiring/soldering is at fault, I'd just roll it up and put it away until you have a new one.
If you get a meter, check for continuity between pins 1+2,1+3 and 2+3 at one end of the cable, with the cable unplugged. You shouldn't get anything.
Now check between 1+1, 2+2 and 3+3 across the length of the cable. You should read continuity with each pair.
If the cable checks out, turn the meter to DC voltage and read between 1+2, and 1+3 with phantom on.
You should read +48V DC each time.
If all that checks out too, I guess the mic isn't working.
Duno if this is useful to you or not.
Phantom power is supplied to a balanced audio connection.
If for some
reason your XLR cable was unbalanced, or if one of the wires was broken/not connected, phantom power wouldn't be applied.