There's so much misinformation about the sound the POD should make. Some say loud "clack"; others say thump. Still others report that they don't get any sound from it. Sound won't tell you anything, because the camera sometimes can work to some extent even if the POD is missing.
If your camera isn't working correctly, the first thing to do is make sure the battery compartment is clean, the battery is at full charge, and the wiring from the battery compartment is sound. The second thing is to check the condition of the POD by taking off the top of the camera and looking at it. If the POD is missing or deteriorated, replace it. Instructions for doing that are at various places on the internet. Finally, if the POD is good, open the bottom of the camera and check the adjustment of the shutter switch rods. There are instructions on the net for doing that, too.
If it still isn't working right, you have a bigger problem than the POD or rod adjustment. Sometimes it's something you might be able to fix yourself, or it might be something you'll have to have done by a qualified repairman such as Mark Hama. Some people say toss the old camera and buy another one from a thrift shop, but unless you get a later GSN/GTN (some of them have better POD material), chances are you're going to get a variation of the same problems.