I have upright Kenmore 2539280213 frostfree freezer. Copper tube at rear of freezer near the floor is dripping water, probably from condensation. I believe the tube leads to the compressor (but don't know for sure). Also ice occasionally forms on floor of freezer interior. Drain pan is dry. Freon has never been added in case that is an issue. Freezer is freezing just fine otherwise.

So first question, can someone tell me where the "drain tube" might be so I can make sure it's not frozen up, etc.

And most importantly, what can we try to do to fix the "leaking" copper tube?
Since the unit is getting old, I don't feel like investing in a technician call when I feel I could get a new freezer on sale instead.

Thanks in advance.