Can I test a XLR microphone with a DMM?
it's a moving coil dynamic. microphone so a resistance mesurement between the signal pins (pins 2 and 3) should show a few hundered ohms. the microphone may emit a clicking sound during the measurement this is normal.

measurement from pin 1 should show no connection to the other pins.

the cable on the on the other hand should be taking a few miliamperes from the microphone socket, (you'll need to make up a an adaptor so you can measure the current going into the microphone cable also measure the voltage on the plug it shopuld be about 1 to 4 volts.

the other test is to put a signal on the XLR input end of the cable, it only need to be a few millivolts, you could use bare loudspeaker driver and shout into it - you should get some audio outof the cable - so run some software tha graphs what it hears on the microphone socket.

As @PeterBennet prompts me. the microphone cable could be just a plain cable with no in-built circuitry. if that's the case it's not going to work with a direct connection to the PC.