5 pins???
At most, three, for a balanced connection, or stereo - but if it's going into a DI box, it's just two - one for tip and one for sleeve.
The test is simple.
Make sure you are on the lowest resistance setting.
Touch the two test probes together - check the meter reads 0 or very close.
with thumb and forefinger, put one probe on the tip of the jack, with it's cover off. It should sit there in the narrower 'dimple' quite happily. The other probe then needs to be touched to each of the connections in turn. When you find one that the meter says is a short - as in 0 Ohms, that is the one connected to the tip of the jack, so it's your hot connection. Then put the probe on the sleeve, not the tip, and repeat the test. As soon as you find one connection that reads 0 Ohms, it is the cold connection. It's very, very simple. The biggest snag is dexterity - keeping the probe connected to the jack with two fingers, while prodding with the other hand.